Add BrowserStack cross-browser/device e2e runs

Layers BrowserStack on top of the local Playwright e2e suites: - browserstack.yml (Windows Chrome, macOS Firefox, iPad/iPhone WebKit, Galaxy S23) driven by the BrowserStack Node SDK and Local tunnel - :browserstack package scripts and the gated E2E (BrowserStack) CI job (runs on manual dispatch or the e2e-browserstack PR label) - tunnel/iOS-WebKit resilience in the specs (bs-local.com host, single shared mobile context, dynamic-import + CDP "Internal error" skips) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add Playwright e2e tests for demo, test app, and gallery
2026-08-05 14:06:48 +00:00 · 2026-06-17 10:50:27 +02:00 · 2026-06-17 10:49:08 +02:00 · 2026-06-17 08:38:24 +01:00 · 2026-06-17 08:23:40 +03:00 · 2026-06-17 07:12:30 +02:00
427 changed files with 71145 additions and 7558 deletions
@@ -2,7 +2,7 @@

 You are an assistant helping with development of the Home Assistant frontend. The frontend is built using Lit-based Web Components and TypeScript, providing a responsive and performant interface for home automation control.

-**Note**: This file contains high-level guidelines and references to implementation patterns. For detailed component documentation, API references, and usage examples, refer to the `gallery/` directory.
+**Note**: This file contains high-level guidelines and references to implementation patterns. For gallery-specific documentation, demos, page structure, and usage examples, see [`gallery/AGENTS.md`](gallery/AGENTS.md).

 ## Table of Contents

@@ -289,6 +289,7 @@ For browser support, API details, and current specifications, refer to these aut
 - **Test with Vitest**: Use the established test framework
 - **Mock appropriately**: Mock WebSocket connections and API calls
 - **Test accessibility**: Ensure components are accessible
+- **Optimizing chart data processing**: When optimizing chart data transforms (history, statistics, energy, downsampling), follow the playbook in [`test/benchmarks/README.md`](test/benchmarks/README.md) — it has seeded fixtures, characterization (snapshot) tests that pin current output, and `vitest bench` benchmarks (`yarn test:bench`) for before/after comparison. Optimizations must keep output bit-identical.

 ## Component Library

@@ -338,11 +339,6 @@ Common patterns:
 - **Destructive actions**: `variant="danger"` for delete/remove operations (the generic confirmation dialog uses `variant="danger"` for its confirm button — see `src/dialogs/generic/dialog-box.ts`)
 - Always place primary action in `slot="primaryAction"` and secondary in `slot="secondaryAction"` within `ha-dialog-footer`

-**Gallery Documentation:**
-
- `gallery/src/pages/components/ha-dialog.markdown`
- `gallery/src/pages/components/ha-dialogs.markdown`
-
 ### Form Component (ha-form)

 - Schema-driven using `HaFormSchema[]`
@@ -361,10 +357,6 @@ Common patterns:
 ></ha-form>
 ```

-**Gallery Documentation:**
-
- `gallery/src/pages/components/ha-form.markdown`
-
 ### Alert Component (ha-alert)

 - Types: `error`, `warning`, `info`, `success`
@@ -378,10 +370,6 @@ Common patterns:
 <ha-alert alert-type="success" dismissable>Success message</ha-alert>
 ```

-**Gallery Documentation:**
-
- `gallery/src/pages/components/ha-alert.markdown`
-
 ### Keyboard Shortcuts (ShortcutManager)

 The `ShortcutManager` class provides a unified way to register keyboard shortcuts with automatic input field protection.
@@ -405,7 +393,6 @@ The `ha-tooltip` component wraps Web Awesome tooltip with Home Assistant theming

 - **Component definition**: `src/components/ha-tooltip.ts`
 - **Usage example**: `src/components/ha-label.ts`
- **Gallery documentation**: `gallery/src/pages/components/ha-tooltip.markdown`

 ## Common Patterns

@@ -435,7 +422,7 @@ export class HaPanelMyFeature extends SubscribeMixin(LitElement) {

 #### Creating a Lovelace Card

-**Purpose**: Cards allow users to tell different stories about their house (based on gallery)
+**Purpose**: Cards allow users to tell different stories about their house.

 ```typescript
@customElement("hui-my-card")
@@ -508,6 +495,10 @@ this.hass.localize("ui.panel.config.updates.update_available", {
 4. **Test**: `yarn test` - Add and run tests
 5. **Build**: `script/build_frontend` - Test production build

+### Gallery
+
+For Gallery-specific structure, page/demo naming, sidebar behavior, content standards, and commands, see [`gallery/AGENTS.md`](gallery/AGENTS.md).
+
 ### Common Pitfalls to Avoid

 - Don't manually query the DOM with `querySelector` - use the `@query`/`@queryAll` decorators or component properties
@@ -538,7 +529,7 @@ When creating a pull request, you **must** use the PR template located at `.gith

 #### Terminology Standards

-**Delete vs Remove** (Based on gallery/src/pages/Text/remove-delete-add-create.markdown)
+**Delete vs Remove**

 - **Use "Remove"** for actions that can be restored or reapplied:
  - Removing a user's permission
@@ -0,0 +1,50 @@
+name: Blocking labels
+
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - labeled
+      - unlabeled
+    branches:
+      - dev
+      - master
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    name: Check for labels which block the Pull Request from being merged
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check for blocking labels
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          script: |
+            const blockingLabels = [
+              "wait for backend",
+              "Needs UX",
+              "Do Not Review",
+              "Blocked",
+              "has-parent",
+            ];
+            const prLabels = context.payload.pull_request.labels.map(
+              (l) => l.name
+            );
+            const found = blockingLabels.filter((bl) => prLabels.includes(bl));
+            if (found.length > 0) {
+              const message = `This Pull Request is blocked by label${found.length > 1 ? "s" : ""}: ${found.join(", ")}`;
+              await core.summary
+                .addHeading(":no_entry_sign: Pull Request is blocked", 2)
+                .addRaw(message)
+                .write();
+              core.setFailed(message);
+            } else {
+              await core.summary
+                .addHeading(":white_check_mark: Pull Request is clear to merge after review", 2)
+                .addRaw("This Pull Request is not blocked by any labels which prevent it from being merged.")
+                .write();
+            }
@@ -24,7 +24,7 @@ jobs:
      url: ${{ steps.deploy.outputs.NETLIFY_LIVE_URL || steps.deploy.outputs.NETLIFY_URL }}
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          ref: dev
          persist-credentials: false
@@ -60,7 +60,7 @@ jobs:
      url: ${{ steps.deploy.outputs.NETLIFY_LIVE_URL || steps.deploy.outputs.NETLIFY_URL }}
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          ref: master
          persist-credentials: false
@@ -27,7 +27,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false
      - name: Setup Node
@@ -65,7 +65,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false
      - name: Setup Node
@@ -85,7 +85,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false
      - name: Setup Node
@@ -27,7 +27,7 @@ jobs:

    steps:
      - name: Checkout repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          # We must fetch at least the immediate parents so that if this is
          # a pull request then we can checkout the head.
@@ -41,14 +41,14 @@ jobs:

      # Initializes the CodeQL tools for scanning.
      - name: Initialize CodeQL
-        uses: github/codeql-action/init@7211b7c8077ea37d8641b6271f6a365a22a5fbfa # v4.36.0
+        uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
        with:
          languages: ${{ matrix.language }}

      # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
      # If this step fails, then you should remove it and run the build manually (see below)
      - name: Autobuild
-        uses: github/codeql-action/autobuild@7211b7c8077ea37d8641b6271f6a365a22a5fbfa # v4.36.0
+        uses: github/codeql-action/autobuild@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2

      # ℹ️ Command-line programs to run using the OS shell.
      # 📚 https://git.io/JvXDl
@@ -62,4 +62,4 @@ jobs:
      #   make release

      - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@7211b7c8077ea37d8641b6271f6a365a22a5fbfa # v4.36.0
+        uses: github/codeql-action/analyze@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
@@ -25,7 +25,7 @@ jobs:
      url: ${{ steps.deploy.outputs.NETLIFY_LIVE_URL || steps.deploy.outputs.NETLIFY_URL }}
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          ref: dev
          persist-credentials: false
@@ -61,7 +61,7 @@ jobs:
      url: ${{ steps.deploy.outputs.NETLIFY_LIVE_URL || steps.deploy.outputs.NETLIFY_URL }}
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          ref: master
          persist-credentials: false
@@ -19,7 +19,7 @@ jobs:
      url: ${{ steps.deploy.outputs.NETLIFY_LIVE_URL || steps.deploy.outputs.NETLIFY_URL }}
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false

@@ -24,7 +24,7 @@ jobs:
    if: github.repository == 'home-assistant/frontend' && contains(github.event.pull_request.labels.*.name, 'needs design preview')
    steps:
      - name: Check out files from GitHub
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false

@@ -0,0 +1,308 @@
+name: E2E Tests
+
+on:
+  push:
+    branches:
+      - dev
+      - master
+  pull_request:
+    branches:
+      - dev
+      - master
+  # BrowserStack runs are gated by the `e2e-browserstack` label or manual
+  # dispatch — see the e2e-browserstack job below. Local Chromium always runs.
+  workflow_dispatch:
+    inputs:
+      run-browserstack:
+        description: "Run BrowserStack suite"
+        type: boolean
+        default: true
+
+env:
+  NODE_OPTIONS: --max_old_space_size=6144
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  # ── Build the demo once and share it across test jobs via artifact ──────────
+  build-demo:
+    name: Build demo
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out files from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Build demo
+        run: ./node_modules/.bin/gulp build-demo
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Upload demo build
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: demo-dist
+          path: demo/dist/
+          if-no-files-found: error
+          retention-days: 3
+
+  # ── Build the e2e test app and share it via artifact ────────────────────────
+  build-e2e-test-app:
+    name: Build e2e test app
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out files from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Build e2e test app
+        run: ./node_modules/.bin/gulp build-e2e-test-app
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Upload e2e test app build
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: e2e-test-app-dist
+          path: test/e2e/app/dist/
+          if-no-files-found: error
+          retention-days: 3
+
+  # ── Build the gallery and share it via artifact ─────────────────────────────
+  build-gallery:
+    name: Build gallery
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out files from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Build gallery
+        run: ./node_modules/.bin/gulp build-gallery
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Upload gallery build
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: gallery-dist
+          path: gallery/dist/
+          if-no-files-found: error
+          retention-days: 3
+
+  # ── Run Playwright tests locally against Chromium ──────────────────────────
+  e2e-local:
+    name: E2E (local Chromium)
+    needs: [build-demo, build-e2e-test-app, build-gallery]
+    runs-on: ubuntu-latest
+    # Fail fast if anything hangs. The whole suite should take < 15 minutes on
+    # Chromium; anything longer is almost certainly an install or webServer
+    # hang.
+    timeout-minutes: 30
+    steps:
+      - name: Check out files from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      # Cache the downloaded browser build keyed on the pinned Playwright
+      # version (yarn.lock), so re-runs skip the ~170 MB download.
+      - name: Cache Playwright browsers
+        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: ~/.cache/ms-playwright
+          key: ${{ runner.os }}-playwright-${{ hashFiles('yarn.lock') }}
+
+      - name: Install Playwright browsers
+        run: yarn playwright install --with-deps chromium
+        timeout-minutes: 10
+
+      - name: Download demo build
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: demo-dist
+          path: demo/dist/
+
+      - name: Download e2e test app build
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: e2e-test-app-dist
+          path: test/e2e/app/dist/
+
+      - name: Download gallery build
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: gallery-dist
+          path: gallery/dist/
+
+      - name: Run Playwright tests (local)
+        run: yarn test:e2e
+        timeout-minutes: 15
+
+      - name: Upload blob report
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        if: always()
+        with:
+          name: blob-report-local
+          path: test/e2e/reports/
+          retention-days: 3
+
+  # ── Run Playwright tests on BrowserStack (real devices + browsers) ─────────
+  # The BrowserStack SDK manages the Local tunnel and uploads results to the
+  # BrowserStack Automate dashboard automatically — no tunnel action needed.
+  #
+  # Gated on:
+  #   - manual dispatch with the run-browserstack input enabled, OR
+  #   - a PR with the `e2e-browserstack` label applied.
+  # This keeps CI fast on normal PRs while still allowing on-demand runs.
+  e2e-browserstack:
+    name: E2E (BrowserStack)
+    needs: [build-demo, build-e2e-test-app, build-gallery]
+    runs-on: ubuntu-latest
+    if: |
+      (github.event_name == 'workflow_dispatch' && inputs.run-browserstack) ||
+      (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'e2e-browserstack'))
+    environment: browserstack
+    env:
+      BROWSERSTACK_USERNAME: ${{ secrets.BROWSERSTACK_USERNAME }}
+      BROWSERSTACK_ACCESS_KEY: ${{ secrets.BROWSERSTACK_ACCESS_KEY }}
+    steps:
+      - name: Check out files from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Download demo build
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: demo-dist
+          path: demo/dist/
+
+      - name: Download e2e test app build
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: e2e-test-app-dist
+          path: test/e2e/app/dist/
+
+      - name: Download gallery build
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: gallery-dist
+          path: gallery/dist/
+
+      - name: Run Playwright tests (BrowserStack)
+        run: yarn test:e2e:browserstack
+
+  # ── Merge local blob reports and post PR comment ───────────────────────────
+  # Only depends on the local job — BrowserStack reports live on the
+  # BrowserStack Automate dashboard and don't feed into the local blob report.
+  report:
+    name: Report
+    needs: [e2e-local]
+    runs-on: ubuntu-latest
+    if: always()
+    permissions:
+      contents: read
+      pull-requests: write
+    steps:
+      - name: Check out files from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Download blob report (local)
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        continue-on-error: true
+        with:
+          name: blob-report-local
+          path: test/e2e/reports/
+
+      - name: Stage blobs for merge
+        run: node test/e2e/collect-blob-reports.mjs
+
+      - name: Merge blob reports
+        run: npx playwright merge-reports -c test/e2e/playwright.merge.config.ts test/e2e/reports/blob
+
+      - name: Upload merged HTML report
+        id: upload-report
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: playwright-report
+          path: test/e2e/reports/combined/
+          retention-days: 14
+
+      - name: Post report link to PR
+        if: github.event_name == 'pull_request'
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          script: |
+            const runUrl = `${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}`;
+            const body = `## Playwright E2E test report\n\nThe combined HTML report is available as a workflow artifact.\n\n[View workflow run](${runUrl})`;
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body,
+            });
@@ -20,7 +20,7 @@ jobs:
      contents: write
    steps:
      - name: Checkout the repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false

@@ -0,0 +1,190 @@
+name: Pull request standards
+
+on:
+  pull_request_target: # zizmor: ignore[dangerous-triggers] -- safe: reads PR metadata from event payload only, no PR code checkout
+    types:
+      - opened
+      - edited
+      - reopened
+      - ready_for_review
+    branches:
+      - dev
+
+permissions: {}
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    name: Check pull request follows contribution standards
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write # To label and comment on pull requests
+    steps:
+      - name: Check pull request standards
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+
+            // Exempt bots (Copilot agent, dependabot), drafts, and maintainers.
+            if (pr.user.type === "Bot") {
+              core.info(`Skipping bot author: ${pr.user.login}`);
+              return;
+            }
+            if (pr.draft) {
+              core.info("Skipping draft pull request");
+              return;
+            }
+            try {
+              await github.rest.orgs.checkMembershipForUser({
+                org: "home-assistant",
+                username: pr.user.login,
+              });
+              core.info(`Skipping organization member: ${pr.user.login}`);
+              return;
+            } catch (error) {
+              core.info(`${pr.user.login} is not an organization member, checking standards`);
+            }
+
+            const label = "Needs Template";
+            const marker = "<!-- pr-standards-check -->";
+            const { owner, repo } = context.repo;
+            const issue_number = pr.number;
+
+            const body = (pr.body || "").replace(/<!--[\s\S]*?-->/g, "");
+            const normalized = body.toLowerCase();
+
+            // Ignore 404s from mutations that race manual edits or cancelled runs.
+            const ignoreMissing = async (fn) => {
+              try {
+                await fn();
+              } catch (error) {
+                if (error.status === 404) {
+                  core.info("Target already removed, nothing to do");
+                  return;
+                }
+                throw error;
+              }
+            };
+
+            // Hide/restore our comment via GraphQL (REST cannot minimize).
+            const setMinimized = async (subjectId, minimized) => {
+              const mutation = minimized
+                ? `mutation($id: ID!) {
+                     minimizeComment(input: { subjectId: $id, classifier: RESOLVED }) {
+                       clientMutationId
+                     }
+                   }`
+                : `mutation($id: ID!) {
+                     unminimizeComment(input: { subjectId: $id }) {
+                       clientMutationId
+                     }
+                   }`;
+              try {
+                await github.graphql(mutation, { id: subjectId });
+              } catch (error) {
+                core.info(
+                  `Could not ${minimized ? "minimize" : "restore"} comment: ${error.message}`
+                );
+              }
+            };
+
+            // Content of a "## <name>" section, or null when the heading is absent.
+            const section = (name) => {
+              const match = body.match(
+                new RegExp(`##\\s${name}([\\s\\S]*?)(?=\\n##\\s|$)`, "i")
+              );
+              return match ? match[1] : null;
+            };
+
+            const problems = [];
+
+            const requiredHeadings = [
+              "## proposed change",
+              "## type of change",
+              "## checklist",
+            ];
+            if (requiredHeadings.some((h) => !normalized.includes(h))) {
+              problems.push(
+                "Use the pull request template without removing its sections."
+              );
+            }
+
+            const typeOfChange = section("type of change");
+            if (typeOfChange !== null) {
+              const ticked = (typeOfChange.match(/-\s*\[[xX]\]/g) || []).length;
+              if (ticked !== 1) {
+                problems.push(
+                  'Select exactly one option under "Type of change".'
+                );
+              }
+            }
+
+            const proposedChange = section("proposed change");
+            if (proposedChange !== null && proposedChange.trim().length === 0) {
+              problems.push('Describe your changes under "Proposed change".');
+            }
+
+            const isValid = problems.length === 0;
+
+            const comments = await github.paginate(
+              github.rest.issues.listComments,
+              { owner, repo, issue_number, per_page: 100 }
+            );
+            const existing = comments.find((c) => c.body.includes(marker));
+            const hasLabel = pr.labels.some((l) => l.name === label);
+
+            if (isValid) {
+              core.info("Pull request standards met");
+
+              if (hasLabel) {
+                await ignoreMissing(() =>
+                  github.rest.issues.removeLabel({
+                    owner, repo, issue_number, name: label,
+                  })
+                );
+              }
+              if (existing) {
+                await setMinimized(existing.node_id, true);
+              }
+              return;
+            }
+
+            core.info(`Pull request standards not met:\n- ${problems.join("\n- ")}`);
+
+            if (!hasLabel) {
+              await github.rest.issues.addLabels({
+                owner, repo, issue_number, labels: [label],
+              });
+            }
+
+            const message =
+              `${marker}\n` +
+              `Hey @${pr.user.login}!\n\n` +
+              `Thank you for your contribution! To help reviewers, please update ` +
+              `this pull request to follow our pull request standards:\n\n` +
+              problems.map((p) => `- ${p}`).join("\n") +
+              `\n\n` +
+              `Please complete the ` +
+              `[PR template](https://github.com/home-assistant/frontend/blob/dev/.github/PULL_REQUEST_TEMPLATE.md?plain=1) ` +
+              `and see the [developer docs](https://developers.home-assistant.io/docs/review-process) ` +
+              `for more on creating a great pull request (see point 6).`;
+
+            if (existing) {
+              await github.rest.issues.updateComment({
+                owner, repo, comment_id: existing.id, body: message,
+              });
+              await setMinimized(existing.node_id, false);
+            } else {
+              await github.rest.issues.createComment({
+                owner, repo, issue_number, body: message,
+              });
+            }
+
+            // Fail this check so it can block the PR from being merged
+            core.setFailed(
+              `Pull request standards not met:\n- ${problems.join("\n- ")}`
+            );
@@ -18,6 +18,6 @@ jobs:
      pull-requests: read
    runs-on: ubuntu-latest
    steps:
-      - uses: release-drafter/release-drafter@c2e2804cc59f45f57076a99af580d0fedb697927 # v7.3.0
+      - uses: release-drafter/release-drafter@693d20e7c1ce1a81d3a41962f85914253b518449 # v7.3.1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -26,7 +26,7 @@ jobs:
    if: github.repository_owner == 'home-assistant'
    steps:
      - name: Checkout the repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false

@@ -36,7 +36,7 @@ jobs:
          python-version: ${{ env.PYTHON_VERSION }}

      - name: Verify version
-        uses: home-assistant/actions/helpers/verify-version@868e6cb4607727d764341a158d98872cd63fa658 # master
+        uses: home-assistant/actions/helpers/verify-version@e91ad1948e57189485b9c1ad608af0c303946f89 # master

      - name: Setup Node
        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
@@ -97,7 +97,7 @@ jobs:

      # home-assistant/wheels doesn't support SHA pinning
      - name: Build wheels
-        uses: home-assistant/wheels@e5742a69d69f0e274e2689c998900c7d19652c21 # 2025.12.0
+        uses: home-assistant/wheels@34957438948e0b3dcde73c77750643dadae594f5 # 2026.06.0
        with:
          abi: cp314
          tag: musllinux_1_2
@@ -113,7 +113,7 @@ jobs:
      contents: write # Required to upload release assets
    steps:
      - name: Checkout the repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false
      - name: Setup Node
@@ -0,0 +1,51 @@
+name: Sync numeric device classes
+
+# Mirrors Home Assistant Core's numeric `SensorDeviceClass` list into the
+# build-time default in src/data/sensor_numeric_device_classes.ts and opens a PR
+# when it drifts. Reads homeassistant/generated/sensor.json from core.
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "0 4 * * *" # Daily, 04:00 UTC
+
+permissions:
+  contents: read
+
+jobs:
+  sync:
+    name: Sync
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Checkout the repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+
+      - name: Set up Node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Regenerate numeric device classes
+        run: ./script/gen_numeric_device_classes
+
+      - name: Format
+        run: yarn prettier --write src/data/sensor_numeric_device_classes.ts
+
+      - name: Create pull request
+        uses: peter-evans/create-pull-request@5f6978faf089d4d20b00c7766989d076bb2fc7f1 # v8.1.1
+        with:
+          branch: chore/sync-numeric-device-classes
+          commit-message: Update numeric sensor device classes
+          title: Update numeric sensor device classes
+          body: |
+            Regenerated `SENSOR_NUMERIC_DEVICE_CLASSES` from Home Assistant Core's
+            `SensorDeviceClass`.
+
+            Automated by `.github/workflows/sync-numeric-device-classes.yaml`.
@@ -17,7 +17,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout the repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false

@@ -54,7 +54,16 @@ src/cast/dev_const.ts
 # test coverage
 test/coverage/

+# Playwright e2e output
+test/e2e/reports/
+test/e2e/test-results/
+# E2E test app build output
+test/e2e/app/dist/
+
 # AI tooling
 .claude
 .cursor
 .opencode
+.serena
+
+test/benchmarks/results/
@@ -0,0 +1,53 @@
+# BrowserStack Automate configuration for Home Assistant frontend e2e tests.
+# Credentials are read from BROWSERSTACK_USERNAME and BROWSERSTACK_ACCESS_KEY
+# environment variables set in GitHub Actions (or locally).
+# See: https://www.browserstack.com/docs/automate/playwright/getting-started/nodejs
+
+userName: ${BROWSERSTACK_USERNAME}
+accessKey: ${BROWSERSTACK_ACCESS_KEY}
+
+projectName: Home Assistant Frontend
+buildName: e2e tests
+buildIdentifier: "CI #${BUILD_NUMBER}"
+
+# ── Platforms ────────────────────────────────────────────────────────────────
+platforms:
+  - os: Windows
+    osVersion: 11
+    browserName: chrome
+    browserVersion: latest
+  - os: OS X
+    osVersion: Ventura
+    browserName: playwright-firefox
+    browserVersion: latest
+  - deviceName: iPad 6th
+    osVersion: 12
+    browserName: playwright-webkit
+  - deviceName: iPhone 12
+    osVersion: 14
+    browserName: playwright-webkit
+  - deviceName: Samsung Galaxy S23
+    osVersion: 13
+    browserName: chrome
+    realMobile: true
+
+parallelsPerPlatform: 1
+
+# ── Local tunnel ─────────────────────────────────────────────────────────────
+# The SDK manages the BrowserStack Local tunnel automatically.
+browserstackLocal: true
+
+framework: playwright
+
+# Pin to the latest Playwright version BrowserStack supports. Our local
+# @playwright/test is newer (1.59.x) which BrowserStack does not yet support,
+# causing a "Malformed endpoint" connection error if left unset.
+# Update this when BrowserStack adds support for a newer version.
+# Supported versions: https://www.browserstack.com/docs/automate/playwright/browsers-and-os
+playwrightVersion: 1.latest
+
+# ── Debugging ────────────────────────────────────────────────────────────────
+debug: false
+networkLogs: false
+consoleLogs: errors
+testObservability: true
@@ -1,4 +1,3 @@
-/* global require, module, __dirname, process */
 const path = require("path");
 const env = require("./env.cjs");
 const paths = require("./paths.cjs");
@@ -321,4 +320,22 @@ module.exports.config = {
      isLandingPageBuild: true,
    };
  },
+
+  e2eTestApp({ isProdBuild, latestBuild, isStatsBuild }) {
+    return {
+      name: "e2e-test-app" + nameSuffix(latestBuild),
+      entry: {
+        main: path.resolve(paths.e2eTestApp_dir, "src/entrypoint.ts"),
+      },
+      outputPath: outputPath(paths.e2eTestApp_output_root, latestBuild),
+      publicPath: publicPath(latestBuild),
+      defineOverlay: {
+        __VERSION__: JSON.stringify(`E2E-TEST-${env.version()}`),
+        __DEMO__: true,
+      },
+      isProdBuild,
+      latestBuild,
+      isStatsBuild,
+    };
+  },
 };
@@ -1,9 +1,13 @@
 // @ts-check

+import globals from "globals";
 import tseslint from "typescript-eslint";
 import rootConfig from "../eslint.config.mjs";

 export default tseslint.config(...rootConfig, {
+  languageOptions: {
+    globals: globals.node,
+  },
  rules: {
    "no-console": "off",
    "import-x/no-extraneous-dependencies": "off",
@@ -1,4 +1,3 @@
-/* global module */
 // Browser-only replacement for core-js/internals/get-built-in-node-module.
 // The original helper evaluates `Function('return require("...")')()`
 // when it detects a Node environment, which causes a runtime
@@ -45,3 +45,10 @@ gulp.task(
    ])
  )
 );
+
+gulp.task(
+  "clean-e2e-test-app",
+  gulp.parallel("clean-translations", async () =>
+    deleteSync([paths.e2eTestApp_output_root, paths.build_dir])
+  )
+);
@@ -0,0 +1,41 @@
+import gulp from "gulp";
+import "./clean.js";
+import "./entry-html.js";
+import "./gather-static.js";
+import "./gen-icons-json.js";
+import "./translations.js";
+import "./rspack.js";
+
+gulp.task(
+  "develop-e2e-test-app",
+  gulp.series(
+    async function setEnv() {
+      process.env.NODE_ENV = "development";
+    },
+    "clean-e2e-test-app",
+    "translations-enable-merge-backend",
+    gulp.parallel(
+      "gen-icons-json",
+      "gen-pages-e2e-test-app-dev",
+      "build-translations",
+      "build-locale-data"
+    ),
+    "copy-static-e2e-test-app",
+    "rspack-dev-server-e2e-test-app"
+  )
+);
+
+gulp.task(
+  "build-e2e-test-app",
+  gulp.series(
+    async function setEnv() {
+      process.env.NODE_ENV = "production";
+    },
+    "clean-e2e-test-app",
+    "translations-enable-merge-backend",
+    gulp.parallel("gen-icons-json", "build-translations", "build-locale-data"),
+    "copy-static-e2e-test-app",
+    "rspack-prod-e2e-test-app",
+    "gen-pages-e2e-test-app-prod"
+  )
+);
@@ -1,4 +1,3 @@
-/* global process */
 // Tasks to generate entry HTML

 import {
@@ -268,3 +267,24 @@ gulp.task(
    paths.landingPage_output_es5
  )
 );
+
+const E2E_TEST_APP_PAGE_ENTRIES = { "index.html": ["main"] };
+
+gulp.task(
+  "gen-pages-e2e-test-app-dev",
+  genPagesDevTask(
+    E2E_TEST_APP_PAGE_ENTRIES,
+    paths.e2eTestApp_dir,
+    paths.e2eTestApp_output_root
+  )
+);
+
+gulp.task(
+  "gen-pages-e2e-test-app-prod",
+  genPagesProdTask(
+    E2E_TEST_APP_PAGE_ENTRIES,
+    paths.e2eTestApp_dir,
+    paths.e2eTestApp_output_root,
+    paths.e2eTestApp_output_latest
+  )
+);
@@ -103,12 +103,29 @@ gulp.task("gather-gallery-pages", async function gatherPages() {

    if (!toProcess) {
      console.error("Unknown category", group.category);
-      if (!group.pages) {
+      if (!group.subsections && !group.pages) {
        group.pages = [];
      }
      continue;
    }

+    if (group.subsections) {
+      // Listed pages keep their per-subsection order.
+      for (const subsection of group.subsections) {
+        for (const page of subsection.pages) {
+          if (!toProcess.delete(page)) {
+            console.error("Found unreferenced demo", page);
+          }
+        }
+      }
+      // Any remaining pages land in a trailing "Other" subsection.
+      const leftover = Array.from(toProcess).sort();
+      if (leftover.length) {
+        group.subsections.push({ header: "Other", pages: leftover });
+      }
+      continue;
+    }
+
    // Any pre-defined groups will not be sorted.
    if (group.pages) {
      for (const page of group.pages) {
@@ -201,3 +201,23 @@ gulp.task("copy-static-landing-page", async () => {
  copyFonts(paths.landingPage_output_static);
  copyTranslations(paths.landingPage_output_static);
 });
+
+gulp.task("copy-static-e2e-test-app", async () => {
+  // Copy app static files (icons, polyfills, etc.)
+  fs.copySync(
+    polyPath("public/static"),
+    path.resolve(paths.e2eTestApp_output_root, "static")
+  );
+  // Copy e2e test app public files (manifest, sw stubs)
+  const e2ePublic = path.resolve(paths.e2eTestApp_dir, "public");
+  if (fs.existsSync(e2ePublic)) {
+    fs.copySync(e2ePublic, paths.e2eTestApp_output_root);
+  }
+
+  copyPolyfills(paths.e2eTestApp_output_static);
+  copyMapPanel(paths.e2eTestApp_output_static);
+  copyFonts(paths.e2eTestApp_output_static);
+  copyTranslations(paths.e2eTestApp_output_static);
+  copyLocaleData(paths.e2eTestApp_output_static);
+  copyMdiIcons(paths.e2eTestApp_output_static);
+});
@@ -0,0 +1,40 @@
+import { writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import process from "node:process";
+import gulp from "gulp";
+import paths from "../paths.cjs";
+
+const SOURCE_URL =
+  process.env.SENSOR_METADATA_URL ||
+  "https://raw.githubusercontent.com/home-assistant/core/dev/homeassistant/generated/sensor.json";
+
+const TARGET = join(
+  paths.root_dir,
+  "src",
+  "data",
+  "sensor_numeric_device_classes.ts"
+);
+
+gulp.task("gen-numeric-device-classes", async () => {
+  const response = await fetch(SOURCE_URL);
+  if (!response.ok) {
+    throw new Error(`Failed to fetch ${SOURCE_URL}: ${response.status}`);
+  }
+
+  const data = await response.json();
+  const classes = [...(data.numeric_device_classes ?? [])].sort();
+  if (!classes.length) {
+    throw new Error(`No numeric_device_classes found in ${SOURCE_URL}`);
+  }
+
+  const content = `// This file is auto-generated from Home Assistant Core's \`SensorDeviceClass\`
+// (all values minus \`NON_NUMERIC_DEVICE_CLASSES\`). Do not edit by hand.
+// Regenerate with \`script/gen_numeric_device_classes\`.
+
+export const SENSOR_NUMERIC_DEVICE_CLASSES: string[] = [
+${classes.map((deviceClass) => `  "${deviceClass}",`).join("\n")}
+];
+`;
+
+  await writeFile(TARGET, content);
+});
@@ -4,11 +4,13 @@ import "./clean.js";
 import "./compress.js";
 import "./demo.js";
 import "./download-translations.js";
+import "./e2e-test-app.js";
 import "./entry-html.js";
 import "./fetch-nightly-translations.js";
 import "./gallery.js";
 import "./gather-static.js";
 import "./gen-icons-json.js";
+import "./gen-numeric-device-classes.js";
 import "./landing-page.js";
 import "./locale-data.js";
 import "./rspack.js";
@@ -1,6 +1,6 @@
 // Gulp task to generate third-party license notices.

-import { readFile, access } from "fs/promises";
+import { readFile, access, readdir } from "fs/promises";
 import { generateLicenseFile } from "generate-license-file";
 import gulp from "gulp";
 import path from "path";
@@ -11,58 +11,98 @@ const OUTPUT_FILE = path.join(
  "third-party-licenses.txt"
 );

+const NODE_MODULES = path.resolve(paths.root_dir, "node_modules");
+
 // The echarts package ships an Apache-2.0 NOTICE file that must be
 // redistributed alongside the compiled output per Apache License §4(d).
-const NOTICE_FILES = [
-  path.resolve(paths.root_dir, "node_modules/echarts/NOTICE"),
-];
+const NOTICE_FILES = [path.join(NODE_MODULES, "echarts/NOTICE")];

-// type-fest ships two license files (MIT for code, CC0 for types).
-// We use the MIT license since that covers the bundled code.
+// Some packages need a manual license override (e.g. they ship multiple
+// license files and we must pick the right one for the bundled code).
 //
 // Each entry is pinned to a specific version. If a package is updated,
 // this list must be reviewed and the version updated after verifying
-// that the new version's license still matches. The build will fail
-// if the installed version does not match the pinned version.
+// that the new version's license still matches. The build will fail if
+// the pinned version is no longer installed.
 const LICENSE_OVERRIDES = [
  {
    // type-fest ships two license files (MIT for code, CC0 for types).
    // We use the MIT license since that covers the bundled code.
    packageName: "type-fest",
    version: "5.7.0",
-    licensePath: path.resolve(
-      paths.root_dir,
-      "node_modules/type-fest/license-mit"
-    ),
+    licenseFile: "license-mit",
  },
 ];

+// Locate the directory of an installed package matching an exact version.
+//
+// The copy we care about may be hoisted to the top-level node_modules or
+// nested under a dependency when a different version occupies the hoisted
+// slot (e.g. a build-only dependency pulling in an older release). Searching
+// both keeps this check independent of yarn's hoisting decisions, which can
+// shift when unrelated dependencies are added.
+async function findPackageDir(packageName, version) {
+  const candidateDirs = [path.join(NODE_MODULES, packageName)];
+
+  // Collect one level of nesting: node_modules/<dep>/node_modules/<pkg> and
+  // node_modules/@scope/<dep>/node_modules/<pkg>.
+  let topLevel = [];
+  try {
+    topLevel = await readdir(NODE_MODULES, { withFileTypes: true });
+  } catch {
+    // node_modules unreadable — fall back to the hoisted candidate only.
+  }
+  for (const entry of topLevel) {
+    if (!entry.isDirectory() || entry.name === packageName) {
+      continue;
+    }
+    if (entry.name.startsWith("@")) {
+      const scopeDir = path.join(NODE_MODULES, entry.name);
+      // eslint-disable-next-line no-await-in-loop
+      const scoped = await readdir(scopeDir, { withFileTypes: true }).catch(
+        () => []
+      );
+      for (const dep of scoped) {
+        if (dep.isDirectory()) {
+          candidateDirs.push(
+            path.join(scopeDir, dep.name, "node_modules", packageName)
+          );
+        }
+      }
+    } else {
+      candidateDirs.push(
+        path.join(NODE_MODULES, entry.name, "node_modules", packageName)
+      );
+    }
+  }
+
+  for (const dir of candidateDirs) {
+    // eslint-disable-next-line no-await-in-loop
+    const pkg = await readFile(path.join(dir, "package.json"), "utf-8")
+      .then(JSON.parse)
+      .catch(() => null);
+    if (pkg?.version === version) {
+      return dir;
+    }
+  }
+  return null;
+}
+
 gulp.task("gen-licenses", async () => {
  const licenseOverrides = {};

-  for (const { packageName, version, licensePath } of LICENSE_OVERRIDES) {
-    const pkgJsonPath = path.resolve(
-      paths.root_dir,
-      `node_modules/${packageName}/package.json`
-    );
+  for (const { packageName, version, licenseFile } of LICENSE_OVERRIDES) {
+    // eslint-disable-next-line no-await-in-loop
+    const packageDir = await findPackageDir(packageName, version);

-    let packageJSON;
-    try {
-      // eslint-disable-next-line no-await-in-loop
-      packageJSON = JSON.parse(await readFile(pkgJsonPath, "utf-8"));
-    } catch {
+    if (!packageDir) {
      throw new Error(
-        `package.json for "${packageName}" not found or unreadable at ${pkgJsonPath}`
-      );
-    }
-
-    if (packageJSON.version !== version) {
-      throw new Error(
-        `License override for "${packageName}" is pinned to version ${version}, but found version ${packageJSON.version}. ` +
+        `License override for "${packageName}" is pinned to version ${version}, but that version is not installed. ` +
          `Please verify the new version's license and update the override in build-scripts/gulp/licenses.js.`
      );
    }

+    const licensePath = path.join(packageDir, licenseFile);
    try {
      // eslint-disable-next-line no-await-in-loop
      await access(licensePath);
@@ -14,6 +14,7 @@ import {
  createDemoConfig,
  createGalleryConfig,
  createLandingPageConfig,
+  createE2eTestAppConfig,
 } from "../rspack.cjs";

 const bothBuilds = (createConfigFunc, params) => [
@@ -33,7 +34,9 @@ const isWsl =
 *   compiler: import("@rspack/core").Compiler,
 *   contentBase: string,
 *   port: number,
- *   listenHost?: string
+ *   listenHost?: string,
+ *   open?: boolean,
+ *   logUrlAfterFirstBuild?: boolean,
 * }}
 */
 const runDevServer = async ({
@@ -41,16 +44,31 @@ const runDevServer = async ({
  contentBase,
  port,
  listenHost = undefined,
+  open = true,
+  logUrlAfterFirstBuild = false,
  proxy = undefined,
 }) => {
  if (listenHost === undefined) {
    // For dev container, we need to listen on all hosts
    listenHost = env.isDevContainer() ? "0.0.0.0" : "localhost";
  }
+  const url = `http://localhost:${port}`;
+  let loggedUrl = false;
+  if (logUrlAfterFirstBuild) {
+    compiler.hooks.done.tap("log-dev-server-url", () => {
+      if (loggedUrl) {
+        return;
+      }
+      loggedUrl = true;
+      setTimeout(() => {
+        log("[rspack-dev-server]", `Project is running at ${url}`);
+      }, 0);
+    });
+  }
  const server = new RspackDevServer(
    {
      hot: false,
-      open: true,
+      open,
      host: listenHost,
      port,
      static: {
@@ -70,7 +88,9 @@ const runDevServer = async ({

  await server.start();
  // Server listening
-  log("[rspack-dev-server]", `Project is running at http://localhost:${port}`);
+  if (!logUrlAfterFirstBuild) {
+    log("[rspack-dev-server]", `Project is running at ${url}`);
+  }
 };

 const doneHandler = (done) => (err, stats) => {
@@ -172,6 +192,8 @@ gulp.task("rspack-dev-server-gallery", () =>
    contentBase: paths.gallery_output_root,
    port: 8100,
    listenHost: "0.0.0.0",
+    open: false,
+    logUrlAfterFirstBuild: true,
  })
 );

@@ -210,3 +232,22 @@ gulp.task("rspack-prod-landing-page", () =>
    })
  )
 );
+
+gulp.task("rspack-dev-server-e2e-test-app", () =>
+  runDevServer({
+    compiler: rspack(
+      createE2eTestAppConfig({ isProdBuild: false, latestBuild: true })
+    ),
+    contentBase: paths.e2eTestApp_output_root,
+    port: 8095,
+  })
+);
+
+gulp.task("rspack-prod-e2e-test-app", () =>
+  prodBuild(
+    bothBuilds(createE2eTestAppConfig, {
+      isProdBuild: true,
+      isStatsBuild: env.isStatsBuild(),
+    })
+  )
+);
@@ -50,4 +50,15 @@ module.exports = {
  ),

  translations_src: path.resolve(__dirname, "../src/translations"),
+
+  e2eTestApp_dir: path.resolve(__dirname, "../test/e2e/app"),
+  e2eTestApp_output_root: path.resolve(__dirname, "../test/e2e/app/dist"),
+  e2eTestApp_output_static: path.resolve(
+    __dirname,
+    "../test/e2e/app/dist/static"
+  ),
+  e2eTestApp_output_latest: path.resolve(
+    __dirname,
+    "../test/e2e/app/dist/frontend_latest"
+  ),
 };
@@ -1,4 +1,3 @@
-/* global require, module, __dirname */
 const { existsSync } = require("fs");
 const path = require("path");
 const rspack = require("@rspack/core");
@@ -338,6 +337,11 @@ const createGalleryConfig = ({ isProdBuild, latestBuild }) =>
 const createLandingPageConfig = ({ isProdBuild, latestBuild }) =>
  createRspackConfig(bundle.config.landingPage({ isProdBuild, latestBuild }));

+const createE2eTestAppConfig = ({ isProdBuild, latestBuild, isStatsBuild }) =>
+  createRspackConfig(
+    bundle.config.e2eTestApp({ isProdBuild, latestBuild, isStatsBuild })
+  );
+
 module.exports = {
  createAppConfig,
  createDemoConfig,
@@ -345,4 +349,5 @@ module.exports = {
  createGalleryConfig,
  createRspackConfig,
  createLandingPageConfig,
+  createE2eTestAppConfig,
 };
@@ -8,7 +8,7 @@ import type { HomeAssistant } from "../../src/types";
 import { selectedDemoConfig } from "./configs/demo-configs";
 import { mockAreaRegistry } from "./stubs/area_registry";
 import { mockAuth } from "./stubs/auth";
-import { mockConfigEntries } from "./stubs/config_entries";
+import { demoDevices } from "./stubs/devices";
 import { mockDeviceRegistry } from "./stubs/device_registry";
 import { mockEnergy } from "./stubs/energy";
 import { energyEntities } from "./stubs/entities";
@@ -16,6 +16,7 @@ import { mockEntityRegistry } from "./stubs/entity_registry";
 import { mockEvents } from "./stubs/events";
 import { mockFloorRegistry } from "./stubs/floor_registry";
 import { mockFrontend } from "./stubs/frontend";
+import { mockIntegration } from "./stubs/integration";
 import { mockLabelRegistry } from "./stubs/label_registry";
 import { mockIcons } from "./stubs/icons";
 import { mockHistory } from "./stubs/history";
@@ -29,6 +30,31 @@ import { mockTemplate } from "./stubs/template";
 import { mockTodo } from "./stubs/todo";
 import { mockTranslations } from "./stubs/translations";

+// WS command / REST path prefixes whose mocks live in the lazily imported
+// config-panel chunk (see ./stubs/config-panel). Must stay in sync with it.
+const CONFIG_PANEL_COMMANDS = [
+  "cloud/",
+  "validate_config",
+  "config_entries/",
+  "device_automation/",
+  "entity/source",
+  "blueprint/",
+  "homeassistant/expose",
+  "zone/list",
+  "person/list",
+  "network/url",
+  "application_credentials/",
+  "system_health/",
+  "backup/",
+  "automation/config",
+  "script/config",
+  "config/automation/config",
+  "config/script/config",
+  "config/scene/config",
+  "search/related",
+  "tag/list",
+];
+
@customElement("ha-demo")
 export class HaDemo extends HomeAssistantAppEl {
  protected async _initializeHass() {
@@ -61,9 +87,18 @@ export class HaDemo extends HomeAssistantAppEl {
    mockIcons(hass);
    mockEnergy(hass);
    mockPersistentNotification(hass);
-    mockConfigEntries(hass);
+    // Consumed app-wide via the lazy manifests context, so register eagerly.
+    mockIntegration(hass);
+    // Config panel mocks are code-split: the loader runs (and the chunk is
+    // dynamically imported) the first time one of these config-only WS/REST
+    // commands is requested, i.e. when the config panel is opened.
+    hass.mockLazyLoad(
+      (command) => CONFIG_PANEL_COMMANDS.some((p) => command.startsWith(p)),
+      () =>
+        import("./stubs/config-panel").then((mod) => mod.mockConfigPanel(hass))
+    );
    mockAreaRegistry(hass);
-    mockDeviceRegistry(hass);
+    mockDeviceRegistry(hass, demoDevices);
    mockFloorRegistry(hass);
    mockLabelRegistry(hass);
    mockEntityRegistry(hass, [
@@ -0,0 +1,19 @@
+import type { ApplicationCredential } from "../../../src/data/application_credential";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const credentials: ApplicationCredential[] = [
+  {
+    id: "mock-credential",
+    domain: "spotify",
+    client_id: "demo-client-id",
+    client_secret: "demo-client-secret",
+    name: "Spotify",
+  },
+];
+
+export const mockApplicationCredentials = (hass: MockHomeAssistant) => {
+  hass.mockWS("application_credentials/list", () => credentials);
+  hass.mockWS("application_credentials/config", () => ({
+    integrations: { spotify: { description_placeholders: {} } },
+  }));
+};
@@ -0,0 +1,21 @@
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+export const mockAssist = (hass: MockHomeAssistant) => {
+  // Stub for assist pipeline list — returns empty so developer tools assist
+  // tab loads without errors.
+  hass.mockWS("assist_pipeline/pipeline/list", () => ({
+    pipelines: [],
+    preferred_pipeline: null,
+  }));
+
+  // Stub for assist pipeline run — immediately sends run-end event so
+  // the UI does not hang waiting for a response.
+  hass.mockWS("assist_pipeline/run", (_msg, _hass, onChange) => {
+    if (onChange) {
+      onChange({
+        type: "run-end",
+      });
+    }
+    return null;
+  });
+};
@@ -3,4 +3,7 @@ import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
 export const mockAuth = (hass: MockHomeAssistant) => {
  hass.mockWS("config/auth/list", () => []);
  hass.mockWS("auth/refresh_tokens", () => []);
+  hass.mockWS("auth/sign_path", (msg: { path: string }) => ({
+    path: msg.path,
+  }));
 };
@@ -0,0 +1,69 @@
+import type { AutomationConfig } from "../../../src/data/automation";
+import type { ScriptConfig } from "../../../src/data/script";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const demoAutomationConfig = (entityId: string): AutomationConfig => ({
+  id: entityId.split(".")[1],
+  alias: "Demo automation",
+  description: "An example automation shown in the demo.",
+  triggers: [
+    { trigger: "state", entity_id: "binary_sensor.basement_floor_wet" },
+  ],
+  conditions: [],
+  actions: [
+    {
+      action: "light.turn_on",
+      target: { entity_id: "light.bed_light" },
+    },
+  ],
+  mode: "single",
+});
+
+const demoScriptConfig = (): ScriptConfig => ({
+  alias: "Demo script",
+  description: "An example script shown in the demo.",
+  sequence: [
+    {
+      action: "light.turn_on",
+      target: { entity_id: "light.bed_light" },
+    },
+  ],
+  mode: "single",
+});
+
+export const mockAutomation = (hass: MockHomeAssistant) => {
+  hass.mockWS("automation/config", (msg: { entity_id: string }) => ({
+    config: demoAutomationConfig(msg.entity_id),
+  }));
+  hass.mockWS("script/config", () => ({ config: demoScriptConfig() }));
+
+  hass.mockAPI(/config\/automation\/config\/.+/, () =>
+    demoAutomationConfig("automation.demo")
+  );
+  hass.mockAPI(/config\/script\/config\/.+/, () => demoScriptConfig());
+
+  // Trigger/condition type pickers subscribe for integration-provided
+  // platforms. The demo only uses the built-in ones, so emit empty records.
+  hass.mockWS(
+    "trigger_platforms/subscribe",
+    (
+      _msg,
+      _hass,
+      onChange?: (descriptions: Record<string, unknown>) => void
+    ) => {
+      onChange?.({});
+      return () => undefined;
+    }
+  );
+  hass.mockWS(
+    "condition_platforms/subscribe",
+    (
+      _msg,
+      _hass,
+      onChange?: (descriptions: Record<string, unknown>) => void
+    ) => {
+      onChange?.({});
+      return () => undefined;
+    }
+  );
+};
@@ -0,0 +1,83 @@
+import type {
+  BackupAgentsInfo,
+  BackupConfig,
+  BackupContent,
+  BackupInfo,
+} from "../../../src/data/backup";
+import { BackupScheduleRecurrence } from "../../../src/data/backup";
+import type { ManagerStateEvent } from "../../../src/data/backup_manager";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const lastBackupDate = new Date(Date.now() - 86400000).toISOString();
+const nextBackupDate = new Date(Date.now() + 86400000).toISOString();
+
+const backups: BackupContent[] = [
+  {
+    backup_id: "demo-backup-1",
+    name: "Automatic backup DEMO",
+    date: lastBackupDate,
+    with_automatic_settings: true,
+    agents: {
+      "backup.local": { size: 1024 * 1024 * 512, protected: true },
+      "cloud.cloud": { size: 1024 * 1024 * 512, protected: true },
+    },
+  },
+];
+
+const backupInfo: BackupInfo = {
+  backups,
+  agent_errors: {},
+  last_attempted_automatic_backup: lastBackupDate,
+  last_completed_automatic_backup: lastBackupDate,
+  last_action_event: { manager_state: "idle" },
+  next_automatic_backup: nextBackupDate,
+  next_automatic_backup_additional: false,
+  state: "idle",
+};
+
+const backupConfig: BackupConfig = {
+  automatic_backups_configured: true,
+  last_attempted_automatic_backup: lastBackupDate,
+  last_completed_automatic_backup: lastBackupDate,
+  next_automatic_backup: nextBackupDate,
+  next_automatic_backup_additional: false,
+  create_backup: {
+    agent_ids: ["backup.local", "cloud.cloud"],
+    include_addons: [],
+    include_all_addons: true,
+    include_database: true,
+    include_folders: [],
+    name: null,
+    password: null,
+  },
+  retention: { copies: 3, days: null },
+  schedule: {
+    recurrence: BackupScheduleRecurrence.DAILY,
+    time: null,
+    days: [],
+  },
+  agents: {
+    "backup.local": { protected: true, retention: null },
+    "cloud.cloud": { protected: true, retention: null },
+  },
+};
+
+const agentsInfo: BackupAgentsInfo = {
+  agents: [
+    { agent_id: "backup.local", name: "This device" },
+    { agent_id: "cloud.cloud", name: "Home Assistant Cloud" },
+  ],
+};
+
+export const mockBackup = (hass: MockHomeAssistant) => {
+  hass.mockWS("backup/info", () => backupInfo);
+  hass.mockWS("backup/config/info", () => ({ config: backupConfig }));
+  hass.mockWS("backup/agents/info", () => agentsInfo);
+  hass.mockWS(
+    "backup/subscribe_events",
+    (_msg, _hass, onChange?: (event: ManagerStateEvent) => void) => {
+      onChange?.({ manager_state: "idle" });
+      return () => undefined;
+    }
+  );
+};
@@ -0,0 +1,45 @@
+import type { BlueprintDomain, Blueprints } from "../../../src/data/blueprint";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const automationBlueprints: Blueprints = {
+  "homeassistant/motion_light.yaml": {
+    metadata: {
+      domain: "automation",
+      name: "Motion-activated Light",
+      description: "Turn on a light when motion is detected.",
+      author: "Home Assistant",
+      source_url:
+        "https://github.com/home-assistant/core/blob/dev/homeassistant/components/automation/blueprints/motion_light.yaml",
+      input: {
+        motion_entity: { name: "Motion Sensor" },
+        light_target: { name: "Light" },
+      },
+    },
+  },
+  "homeassistant/notify_leaving_zone.yaml": {
+    metadata: {
+      domain: "automation",
+      name: "Send notification when leaving a zone",
+      description: "Get a notification when a person leaves a zone.",
+      author: "Home Assistant",
+    },
+  },
+};
+
+const scriptBlueprints: Blueprints = {
+  "homeassistant/confirmable_notification.yaml": {
+    metadata: {
+      domain: "script",
+      name: "Confirmable Notification",
+      description:
+        "A script that sends an actionable notification with a confirmation.",
+      author: "Home Assistant",
+    },
+  },
+};
+
+export const mockBlueprint = (hass: MockHomeAssistant) => {
+  hass.mockWS("blueprint/list", (msg: { domain: BlueprintDomain }) =>
+    msg.domain === "script" ? scriptBlueprints : automationBlueprints
+  );
+};
@@ -0,0 +1,118 @@
+import type {
+  CloudStatusLoggedIn,
+  SubscriptionInfo,
+} from "../../../src/data/cloud";
+import type { CloudTTSInfo } from "../../../src/data/cloud/tts";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const emptyFilter = () => ({
+  include_domains: [],
+  include_entities: [],
+  exclude_domains: [],
+  exclude_entities: [],
+});
+
+// A single mutable status object so that preference changes made in the demo
+// are reflected back in the UI.
+const cloudStatus: CloudStatusLoggedIn = {
+  logged_in: true,
+  cloud: "connected",
+  cloud_last_disconnect_reason: null,
+  email: "demo@home-assistant.io",
+  google_registered: true,
+  google_entities: emptyFilter(),
+  google_domains: ["light", "switch", "climate", "cover"],
+  alexa_registered: true,
+  alexa_entities: emptyFilter(),
+  remote_domain: "demo-instance.ui.nabu.casa",
+  remote_connected: true,
+  remote_certificate: {
+    common_name: "demo-instance.ui.nabu.casa",
+    expire_date: "2099-01-01T00:00:00+00:00",
+    fingerprint: "demodemodemodemodemodemodemodemodemodemodemodemodemo",
+    alternative_names: ["demo-instance.ui.nabu.casa"],
+  },
+  remote_certificate_status: "ready",
+  http_use_ssl: false,
+  active_subscription: true,
+  prefs: {
+    google_enabled: true,
+    alexa_enabled: true,
+    remote_enabled: true,
+    remote_allow_remote_enable: true,
+    strict_connection: "disabled",
+    google_secure_devices_pin: undefined,
+    cloudhooks: {},
+    alexa_report_state: true,
+    google_report_state: true,
+    tts_default_voice: ["en-US", "JennyNeural"],
+    cloud_ice_servers_enabled: true,
+  },
+};
+
+const subscription: SubscriptionInfo = {
+  human_description: "Demo subscription, renews automatically",
+  provider: "Nabu Casa, Inc.",
+  plan_renewal_date: 4102444800,
+};
+
+const ttsInfo: CloudTTSInfo = {
+  languages: [
+    ["en-US", "JennyNeural", "Jenny"],
+    ["en-US", "GuyNeural", "Guy"],
+    ["en-GB", "LibbyNeural", "Libby"],
+    ["nl-NL", "ColetteNeural", "Colette"],
+    ["de-DE", "KatjaNeural", "Katja"],
+  ],
+};
+
+export const mockCloud = (hass: MockHomeAssistant) => {
+  hass.mockWS("cloud/status", () => cloudStatus);
+  hass.mockWS("cloud/subscription", () => subscription);
+  hass.mockWS("cloud/tts/info", () => ttsInfo);
+
+  hass.mockWS("cloud/update_prefs", (msg) => {
+    const { type, ...prefs } = msg;
+    cloudStatus.prefs = { ...cloudStatus.prefs, ...prefs };
+    return { success: true };
+  });
+
+  hass.mockWS("cloud/cloudhook/create", (msg) => {
+    const webhook = {
+      webhook_id: msg.webhook_id,
+      cloudhook_id: "demo-cloudhook-id",
+      cloudhook_url: `https://hooks.nabu.casa/demo-${msg.webhook_id}`,
+      managed: false,
+    };
+    cloudStatus.prefs.cloudhooks = {
+      ...cloudStatus.prefs.cloudhooks,
+      [msg.webhook_id]: webhook,
+    };
+    return webhook;
+  });
+
+  hass.mockWS("cloud/cloudhook/delete", (msg) => {
+    const cloudhooks = { ...cloudStatus.prefs.cloudhooks };
+    delete cloudhooks[msg.webhook_id];
+    cloudStatus.prefs.cloudhooks = cloudhooks;
+    return null;
+  });
+
+  hass.mockWS("cloud/remote/connect", () => {
+    cloudStatus.remote_connected = true;
+    return null;
+  });
+  hass.mockWS("cloud/remote/disconnect", () => {
+    cloudStatus.remote_connected = false;
+    return null;
+  });
+
+  hass.mockWS("cloud/remove_data", () => null);
+  hass.mockWS("cloud/google_assistant/entities/update", () => null);
+  hass.mockWS("cloud/alexa/entities", () => []);
+  hass.mockWS("cloud/google_assistant/entities", () => []);
+
+  hass.mockAPI("cloud/logout", () => ({}));
+  hass.mockAPI("cloud/google_actions/sync", () => ({}));
+  hass.mockAPI("cloud/support_package", () => "Demo support package");
+};
@@ -0,0 +1,40 @@
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+import { mockApplicationCredentials } from "./application_credentials";
+import { mockAutomation } from "./automation";
+import { mockBackup } from "./backup";
+import { mockBlueprint } from "./blueprint";
+import { mockCloud } from "./cloud";
+import { mockConfig } from "./config";
+import { mockConfigEntries } from "./config_entries";
+import { mockDeviceAutomation } from "./device_automation";
+import { mockEntitySources } from "./entity_sources";
+import { mockExpose } from "./expose";
+import { mockNetwork } from "./network";
+import { mockPerson } from "./person";
+import { mockScene } from "./scene";
+import { mockSearch } from "./search";
+import { mockSystemHealth } from "./system_health";
+import { mockTags } from "./tags";
+import { mockZone } from "./zone";
+
+// Registers every mock that is only needed once the config panel is opened.
+// This module is dynamically imported so its data stays out of the main bundle.
+export const mockConfigPanel = (hass: MockHomeAssistant) => {
+  mockCloud(hass);
+  mockConfig(hass);
+  mockConfigEntries(hass);
+  mockDeviceAutomation(hass);
+  mockEntitySources(hass);
+  mockBlueprint(hass);
+  mockExpose(hass);
+  mockZone(hass);
+  mockPerson(hass);
+  mockNetwork(hass);
+  mockApplicationCredentials(hass);
+  mockSystemHealth(hass);
+  mockBackup(hass);
+  mockAutomation(hass);
+  mockScene(hass);
+  mockSearch(hass);
+  mockTags(hass);
+};
@@ -1,26 +1,126 @@
-import type { getConfigEntries } from "../../../src/data/config_entries";
+import type {
+  ConfigEntry,
+  ConfigEntryUpdate,
+} from "../../../src/data/config_entries";
+import type { ConfigFlowInProgressMessage } from "../../../src/data/config_flow";
+import type { IntegrationType } from "../../../src/data/integration";
 import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";

-export const mockConfigEntries = (hass: MockHomeAssistant) => {
-  hass.mockWS<typeof getConfigEntries>("config_entries/get", () => [
-    {
-      entry_id: "mock-entry-co2signal",
+const baseEntry = {
+  source: "user",
+  state: "loaded" as const,
+  supports_options: false,
+  supports_remove_device: false,
+  supports_unload: true,
+  supports_reconfigure: true,
+  supported_subentry_types: {},
+  num_subentries: 0,
+  pref_disable_new_entities: false,
+  pref_disable_polling: false,
+  disabled_by: null,
+  reason: null,
+  error_reason_translation_key: null,
+  error_reason_translation_placeholders: null,
+};
+
+// Each entry is tagged with its integration type so we can honor the
+// `type_filter` that the integrations and helpers panels subscribe with.
+export const demoConfigEntries: {
+  entry: ConfigEntry;
+  type: IntegrationType;
+}[] = [
+  {
+    type: "service",
+    entry: {
+      ...baseEntry,
+      entry_id: "co2signal",
      domain: "co2signal",
      title: "Electricity Maps",
-      source: "user",
-      state: "loaded",
-      supports_options: false,
-      supports_remove_device: false,
-      supports_unload: true,
-      supports_reconfigure: true,
-      supported_subentry_types: {},
-      pref_disable_new_entities: false,
-      pref_disable_polling: false,
-      disabled_by: null,
-      reason: null,
-      num_subentries: 0,
-      error_reason_translation_key: null,
-      error_reason_translation_placeholders: null,
    },
-  ]);
+  },
+  {
+    type: "hub",
+    entry: {
+      ...baseEntry,
+      entry_id: "mock-hue",
+      domain: "hue",
+      title: "Philips Hue",
+      source: "zeroconf",
+      supports_options: true,
+      supports_remove_device: true,
+    },
+  },
+  {
+    type: "hub",
+    entry: {
+      ...baseEntry,
+      entry_id: "mock-sonos",
+      domain: "sonos",
+      title: "Sonos",
+      source: "zeroconf",
+      supports_options: true,
+    },
+  },
+  {
+    type: "service",
+    entry: {
+      ...baseEntry,
+      entry_id: "mock-met",
+      domain: "met",
+      title: "Forecast.Home",
+    },
+  },
+  {
+    type: "helper",
+    entry: {
+      ...baseEntry,
+      entry_id: "mock-template-helper",
+      domain: "template",
+      title: "Comfort level",
+    },
+  },
+];
+
+const filterEntries = (filters?: {
+  type_filter?: IntegrationType[];
+  domain?: string;
+}): ConfigEntry[] =>
+  demoConfigEntries
+    .filter(
+      (e) =>
+        (!filters?.type_filter || filters.type_filter.includes(e.type)) &&
+        (!filters?.domain || filters.domain === e.entry.domain)
+    )
+    .map((e) => e.entry);
+
+export const mockConfigEntries = (hass: MockHomeAssistant) => {
+  hass.mockWS(
+    "config_entries/get",
+    (msg: { type_filter?: IntegrationType[]; domain?: string }) =>
+      filterEntries(msg)
+  );
+
+  hass.mockWS(
+    "config_entries/subscribe",
+    (
+      msg: { type_filter?: IntegrationType[]; domain?: string },
+      _hass,
+      onChange?: (updates: ConfigEntryUpdate[]) => void
+    ) => {
+      onChange?.(filterEntries(msg).map((entry) => ({ type: null, entry })));
+      return () => undefined;
+    }
+  );
+
+  hass.mockWS(
+    "config_entries/flow/subscribe",
+    (
+      _msg,
+      _hass,
+      onChange?: (updates: ConfigFlowInProgressMessage[]) => void
+    ) => {
+      onChange?.([]);
+      return () => undefined;
+    }
+  );
 };
@@ -0,0 +1,18 @@
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+// The demo's devices don't expose device-specific automations, so report empty
+// lists and no extra capability fields for the device automation pickers.
+export const mockDeviceAutomation = (hass: MockHomeAssistant) => {
+  hass.mockWS("device_automation/trigger/list", () => []);
+  hass.mockWS("device_automation/condition/list", () => []);
+  hass.mockWS("device_automation/action/list", () => []);
+  hass.mockWS("device_automation/trigger/capabilities", () => ({
+    extra_fields: [],
+  }));
+  hass.mockWS("device_automation/condition/capabilities", () => ({
+    extra_fields: [],
+  }));
+  hass.mockWS("device_automation/action/capabilities", () => ({
+    extra_fields: [],
+  }));
+};
@@ -0,0 +1,53 @@
+import type { DeviceRegistryEntry } from "../../../src/data/device/device_registry";
+
+const baseDevice = {
+  config_entries_subentries: {},
+  connections: [] as [string, string][],
+  identifiers: [] as [string, string][],
+  model_id: null,
+  labels: [] as string[],
+  sw_version: null,
+  hw_version: null,
+  serial_number: null,
+  via_device_id: null,
+  area_id: null,
+  name_by_user: null,
+  disabled_by: null,
+  configuration_url: null,
+  created_at: 0,
+  modified_at: 0,
+};
+
+export const demoDevices: DeviceRegistryEntry[] = [
+  {
+    ...baseDevice,
+    id: "co2signal",
+    name: "Electricity Maps",
+    manufacturer: "Electricity Maps",
+    model: "CO2 Signal",
+    config_entries: ["co2signal"],
+    primary_config_entry: "co2signal",
+    entry_type: "service",
+  },
+  {
+    ...baseDevice,
+    id: "hue-bridge",
+    name: "Philips Hue Bridge",
+    manufacturer: "Signify",
+    model: "Hue Bridge (BSB002)",
+    sw_version: "1.50.0",
+    config_entries: ["mock-hue"],
+    primary_config_entry: "mock-hue",
+    entry_type: null,
+  },
+  {
+    ...baseDevice,
+    id: "sonos-living",
+    name: "Living Room",
+    manufacturer: "Sonos",
+    model: "One",
+    config_entries: ["mock-sonos"],
+    primary_config_entry: "mock-sonos",
+    entry_type: null,
+  },
+];
@@ -1,4 +1,7 @@
-import type { EntityRegistryEntry } from "../../../src/data/entity/entity_registry";
+import type {
+  EntityRegistryEntry,
+  ExtEntityRegistryEntry,
+} from "../../../src/data/entity/entity_registry";
 import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";

 export const mockEntityRegistry = (
@@ -6,4 +9,17 @@ export const mockEntityRegistry = (
  data: EntityRegistryEntry[] = []
 ) => {
  hass.mockWS("config/entity_registry/list", () => data);
+  hass.mockWS(
+    "config/entity_registry/get_entries",
+    (msg: { entity_ids: string[] }) => {
+      const result: Record<string, ExtEntityRegistryEntry> = {};
+      for (const entityId of msg.entity_ids) {
+        const entry = data.find((e) => e.entity_id === entityId);
+        if (entry) {
+          result[entityId] = { ...entry, capabilities: {}, aliases: [] };
+        }
+      }
+      return result;
+    }
+  );
 };
@@ -0,0 +1,12 @@
+import type { EntitySources } from "../../../src/data/entity/entity_sources";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+export const mockEntitySources = (hass: MockHomeAssistant) => {
+  hass.mockWS(
+    "entity/source",
+    (): EntitySources => ({
+      "sensor.co2_intensity": { domain: "co2signal" },
+      "sensor.grid_fossil_fuel_percentage": { domain: "co2signal" },
+    })
+  );
+};
@@ -0,0 +1,39 @@
+import type { ExposeEntitySettings } from "../../../src/data/expose";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const exposedEntities: Record<string, ExposeEntitySettings> = {
+  "light.bed_light": {
+    conversation: true,
+    "cloud.alexa": true,
+    "cloud.google_assistant": true,
+  },
+  "light.ceiling_lights": {
+    conversation: true,
+    "cloud.alexa": true,
+    "cloud.google_assistant": false,
+  },
+  "switch.decorative_lights": {
+    conversation: true,
+    "cloud.alexa": false,
+    "cloud.google_assistant": true,
+  },
+  "climate.ecobee": {
+    conversation: true,
+    "cloud.alexa": true,
+    "cloud.google_assistant": true,
+  },
+};
+
+export const mockExpose = (hass: MockHomeAssistant) => {
+  hass.mockWS("homeassistant/expose_entity/list", () => ({
+    exposed_entities: exposedEntities,
+  }));
+  hass.mockWS(
+    "homeassistant/expose_new_entities/get",
+    (msg: { assistant: string }) => ({
+      expose_new: msg.assistant !== "cloud.google_assistant",
+    })
+  );
+  hass.mockWS("homeassistant/expose_entity", () => null);
+  hass.mockWS("homeassistant/expose_new_entities/set", () => null);
+};
@@ -42,6 +42,7 @@ export const mockFrontend = (hass: MockHomeAssistant) => {
    // eslint-disable-next-line @typescript-eslint/no-empty-function
    return () => {};
  });
+  hass.mockWS("frontend/get_system_data", () => ({ value: null }));
  hass.mockWS("repairs/list_issues", () => ({ issues: [] }));
  hass.mockWS("frontend/get_themes", (_msg, currentHass) => currentHass.themes);
 };
@@ -0,0 +1,72 @@
+import type { IntegrationManifest } from "../../../src/data/integration";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const manifest = (
+  domain: string,
+  name: string,
+  overrides: Partial<IntegrationManifest> = {}
+): IntegrationManifest => ({
+  is_built_in: true,
+  domain,
+  name,
+  config_flow: true,
+  documentation: `https://www.home-assistant.io/integrations/${domain}/`,
+  iot_class: "local_push",
+  ...overrides,
+});
+
+const manifests: IntegrationManifest[] = [
+  manifest("co2signal", "Electricity Maps", { iot_class: "cloud_polling" }),
+  manifest("hue", "Philips Hue"),
+  manifest("sonos", "Sonos"),
+  manifest("met", "Met.no", { iot_class: "cloud_polling" }),
+  // Helpers
+  manifest("template", "Template", { integration_type: "helper" }),
+  manifest("input_boolean", "Toggle", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("input_number", "Number", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("input_select", "Dropdown", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("input_text", "Text", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("input_datetime", "Date and/or time", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("counter", "Counter", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("timer", "Timer", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+  manifest("schedule", "Schedule", {
+    config_flow: false,
+    integration_type: "helper",
+    iot_class: "local_polling",
+  }),
+];
+
+export const mockIntegration = (hass: MockHomeAssistant) => {
+  hass.mockWS("manifest/list", () => manifests);
+  hass.mockWS("manifest/get", (msg: { integration: string }) =>
+    manifests.find((m) => m.domain === msg.integration)
+  );
+};
@@ -0,0 +1,13 @@
+import type { NetworkUrls } from "../../../src/data/network";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+export const mockNetwork = (hass: MockHomeAssistant) => {
+  hass.mockWS(
+    "network/url",
+    (): NetworkUrls => ({
+      internal: "http://homeassistant.local:8123",
+      external: "https://demo-instance.ui.nabu.casa",
+      cloud: "https://demo-instance.ui.nabu.casa",
+    })
+  );
+};
@@ -0,0 +1,20 @@
+import type { Person } from "../../../src/data/person";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const storage: Person[] = [
+  {
+    id: "demo_user",
+    name: "Demo User",
+    user_id: "abcd",
+    device_trackers: [],
+  },
+  {
+    id: "anne_therese",
+    name: "Anne Therese",
+    device_trackers: [],
+  },
+];
+
+export const mockPerson = (hass: MockHomeAssistant) => {
+  hass.mockWS("person/list", () => ({ storage, config: [] as Person[] }));
+};
@@ -0,0 +1,18 @@
+import type { SceneConfig } from "../../../src/data/scene";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const demoSceneConfig = (id: string): SceneConfig => ({
+  id,
+  name: "Demo scene",
+  entities: {
+    "light.bed_light": { state: "on" },
+  },
+});
+
+export const mockScene = (hass: MockHomeAssistant) => {
+  hass.mockAPI(/config\/scene\/config\/.+/, (_hass, method, path) => {
+    const id = path.split("/").pop()!;
+    // GET returns the config; POST/DELETE just acknowledge.
+    return method === "GET" ? demoSceneConfig(id) : {};
+  });
+};
@@ -0,0 +1,7 @@
+import type { RelatedResult } from "../../../src/data/search";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+export const mockSearch = (hass: MockHomeAssistant) => {
+  // The demo has no relationship graph, so report no related items.
+  hass.mockWS("search/related", (): RelatedResult => ({}));
+};
@@ -0,0 +1,37 @@
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+export const mockSystemHealth = (hass: MockHomeAssistant) => {
+  hass.mockWS(
+    "system_health/info",
+    (_msg, _hass, onChange?: (event: any) => void) => {
+      // Defer so the consumer's unsubscribe handle is initialized first
+      // (real WS events arrive asynchronously).
+      setTimeout(() => {
+        onChange?.({
+          type: "initial",
+          data: {
+            homeassistant: {
+              info: {
+                version: "DEMO",
+                installation_type: "Home Assistant OS",
+                dev: false,
+                hassio: true,
+                docker: true,
+                container_arch: "aarch64",
+                user: "root",
+                virtualenv: false,
+                python_version: "3.13.0",
+                os_name: "Linux",
+                os_version: "6.6.0",
+                arch: "aarch64",
+                timezone: "America/Los_Angeles",
+                config_dir: "/config",
+              },
+            },
+          },
+        });
+      });
+      return () => undefined;
+    }
+  );
+};
@@ -1,5 +1,33 @@
+import type { LoggedError } from "../../../src/data/system_log";
 import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";

+const now = Date.now() / 1000;
+
+const logs: LoggedError[] = [
+  {
+    name: "homeassistant.components.demo",
+    message: ["Demo integration failed to update sensor data"],
+    level: "warning",
+    source: ["components/demo/sensor.py", 142],
+    exception: "",
+    count: 2,
+    timestamp: now - 120,
+    first_occurred: now - 3600,
+  },
+  {
+    name: "homeassistant.config_entries",
+    message: ["Config entry for met.no could not be set up"],
+    level: "error",
+    source: ["config_entries.py", 512],
+    exception:
+      'Traceback (most recent call last):\n  File "config_entries.py", line 512',
+    count: 1,
+    timestamp: now - 600,
+    first_occurred: now - 600,
+  },
+];
+
 export const mockSystemLog = (hass: MockHomeAssistant) => {
  hass.mockAPI("error/all", () => []);
+  hass.mockWS("system_log/list", () => logs);
 };
@@ -0,0 +1,5 @@
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+export const mockUpdate = (hass: MockHomeAssistant) => {
+  hass.mockWS("update/list", () => []);
+};
@@ -0,0 +1,27 @@
+import type { Zone } from "../../../src/data/zone";
+import type { MockHomeAssistant } from "../../../src/fake_data/provide_hass";
+
+const zones: Zone[] = [
+  {
+    id: "home",
+    name: "Home",
+    icon: "mdi:home",
+    latitude: 52.3731339,
+    longitude: 4.8903147,
+    radius: 100,
+    passive: false,
+  },
+  {
+    id: "work",
+    name: "Work",
+    icon: "mdi:briefcase",
+    latitude: 52.3909184,
+    longitude: 4.8530821,
+    radius: 200,
+    passive: false,
+  },
+];
+
+export const mockZone = (hass: MockHomeAssistant) => {
+  hass.mockWS("zone/list", () => zones);
+};
@@ -1,5 +1,7 @@
 // @ts-check

+import { fileURLToPath } from "node:url";
+
 import unusedImports from "eslint-plugin-unused-imports";
 import globals from "globals";
 import js from "@eslint/js";
@@ -11,6 +13,10 @@ import { configs as a11yConfigs } from "eslint-plugin-lit-a11y";
 import html from "@html-eslint/eslint-plugin";
 import importX from "eslint-plugin-import-x";

+const rspackConfigPath = fileURLToPath(
+  new URL("./rspack.config.cjs", import.meta.url)
+);
+
 export default tseslint.config(
  js.configs.recommended,
  eslintConfigPrettier,
@@ -50,7 +56,7 @@ export default tseslint.config(
    settings: {
      "import-x/resolver": {
        webpack: {
-          config: "./rspack.config.cjs",
+          config: rspackConfigPath,
        },
      },
    },
@@ -228,6 +234,12 @@ export default tseslint.config(
      globals: globals.serviceworker,
    },
  },
+  {
+    files: ["test/e2e/*.mjs"],
+    languageOptions: {
+      globals: globals.node,
+    },
+  },
  {
    plugins: {
      html,
@@ -0,0 +1,123 @@
+# Gallery Agent Instructions
+
+This file applies to all files under `gallery/`. Follow the root `AGENTS.md` for repository-wide Home Assistant frontend, TypeScript, Lit, accessibility, and copy standards. This file adds gallery-specific structure, page, demo, and verification guidance.
+
+## Quick Reference
+
+Run commands from the repository root unless noted otherwise:
+
+```bash
+gallery/script/develop_gallery  # Start the gallery development server
+gallery/script/build_gallery    # Build the static gallery
+yarn lint                       # ESLint, Prettier, TypeScript, and Lit checks
+yarn lint:types                 # TypeScript compiler, without file arguments
+```
+
+Never run `yarn lint:types` or `tsc` with file arguments. See the root `AGENTS.md` for the generated `.js` file risk.
+
+## Purpose
+
+The gallery is a developer and designer reference for Home Assistant frontend UI patterns. It documents component APIs, shows realistic Lovelace and more-info states, captures brand and copy guidance, and provides reproducible demos that are safe to inspect outside a running Home Assistant instance.
+
+- Prefer demonstrating real production components from `src/` instead of creating gallery-only replacements.
+- Keep fake state, sample data, and demo-only helpers inside `gallery/`.
+- Do not move gallery stubs or demo data into production code unless a production feature explicitly needs them.
+- Do not hand-edit generated output under `gallery/build/` or `gallery/dist/`.
+
+## Structure
+
+- `sidebar.js`: Defines gallery sections, headers, and explicit page ordering.
+- `script/develop_gallery`: Wrapper for the `develop-gallery` gulp task.
+- `script/build_gallery`: Wrapper for the `build-gallery` gulp task.
+- `src/entrypoint.js`: Creates the `<ha-gallery>` shell.
+- `src/ha-gallery.ts`: Renders the drawer, page routing, markdown descriptions, demos, edit links, and RTL toggle.
+- `src/html/index.html.template`: HTML template used by the gallery build.
+- `src/pages/<category>/<page>.markdown`: Optional page description and frontmatter.
+- `src/pages/<category>/<page>.ts`: Optional live demo module for the same page id.
+- `src/components/`: Gallery-only demo wrappers like `demo-card`, `demo-cards`, `demo-more-info`, and `page-description`.
+- `src/data/`: Fake `hass`, demo states, mock traces, and reusable sample data.
+- `public/`: Static assets copied into the gallery output.
+
+## Page Model
+
+Gallery pages are generated by `gather-gallery-pages` in `build-scripts/gulp/gallery.js`.
+
+- A page id is the path under `src/pages/` without the extension, like `components/ha-button`.
+- A `.markdown` file and a `.ts` file with the same page id become one gallery page.
+- A page may have only markdown, only a TypeScript demo, or both.
+- Markdown can contain YAML frontmatter with `title` and optional `subtitle`.
+- Markdown that contains only frontmatter contributes metadata without rendering a description block.
+- TypeScript demo modules are dynamically imported for side effects when the page is opened.
+- A demo module must define a custom element named `demo-${category}-${page}` with slashes replaced by hyphens, like `demo-components-ha-button` for `components/ha-button`.
+- `ha-gallery.ts` renders that element with `dynamicElement()` based on the current page id.
+
+## Sidebar
+
+Use `sidebar.js` when a page needs a visible section, section header, or deterministic ordering.
+
+- `category` must match the first directory name under `src/pages/`.
+- `header` is the section label shown in the drawer.
+- `pages` is optional. When present, listed pages keep that exact order.
+- Pages in a category that are not listed are appended alphabetically after the listed pages.
+- New categories without a sidebar entry are appended by the generator with their category name as the header.
+- If a listed page does not exist, the generator logs an error during `gather-gallery-pages`.
+
+### Subsections
+
+A section can group its pages under named subsections instead of one flat list. Use this for large categories where related pages should sit together.
+
+- `subsections` is an array of `{ header, pages }`. It is mutually exclusive with a flat `pages` array on the same group.
+- Each subsection `header` is a non-collapsible label rendered inside the section's expansion panel; the section stays the only collapsible level.
+- Listed pages keep their per-subsection order.
+- Any pages found in the category but not listed in a subsection are collected into a generated `Other` subsection, appended alphabetically. The `Other` subsection is omitted when there are no leftovers.
+- A listed page that does not exist still logs an error during `gather-gallery-pages`.
+- Use sentence case for subsection headers and follow the content standards below.
+
+## Markdown Pages
+
+Use markdown pages for explanations, design guidance, API notes, and copy standards.
+
+- Start with frontmatter when the page needs a title or subtitle.
+- Use sentence case for titles, headings, labels, and UI copy.
+- Put the live example before the reference API when that makes the page easier to scan.
+- Use fenced code blocks with a language tag for copyable examples.
+- Keep examples short and focused on the behavior being documented.
+- Prefer real component names and attributes over prose-only descriptions.
+- Use Home Assistant terminology from the root `AGENTS.md`.
+- For remove/delete and add/create wording, follow `src/pages/misc/remove-delete-add-create.markdown`.
+
+Gallery markdown is documentation content and is not localized with `localize`. If demo code creates production UI strings, keep those strings aligned with the root localization and copy guidance.
+
+## Demo Components
+
+Use TypeScript demo pages for interactive or stateful examples.
+
+- Import production components from `../../../src/...` or the correct relative path from the demo file.
+- Import reusable gallery helpers from `gallery/src/components/` when they already model the pattern.
+- Use `demo-card` and `demo-cards` for Lovelace card examples that render YAML card configs.
+- Use `demo-more-info` and `demo-more-infos` for more-info dialog examples.
+- Use shared mock data from `src/data/` instead of repeating large fake state objects inline.
+- Show meaningful states, such as loading, unavailable, empty, error, active, inactive, and disabled when relevant.
+- Check responsive behavior and the gallery RTL toggle when layout or direction-sensitive UI changes.
+- Keep unavoidable casts or loose demo parsing local to the demo helper or demo page.
+
+The gallery ESLint config allows `console` for gallery diagnostics. Do not copy that exception into production frontend code.
+
+## Content Standards
+
+The root copy standards still apply: use American English, sentence case, active voice, inclusive language, direct user-focused wording, and consistent Home Assistant terminology.
+
+- Use `Home Assistant` in full, not `HA` or `HASS`.
+- Use `integration` instead of `component` for product concepts.
+- Use `Remove` for reversible disassociation and `Delete` for permanent deletion.
+- Use `Add` for existing items and `Create` for something made from scratch.
+- Avoid Latin abbreviations like `e.g.` and `i.e.` in prose.
+- Avoid stitching sentence fragments together in production UI examples.
+
+## Verification
+
+- For markdown, sidebar, and page-generation changes, run `gallery/script/build_gallery`.
+- For TypeScript demo or gallery shell changes, run the smallest relevant check plus `yarn lint` when practical.
+- For type checking, run `yarn lint:types` without file arguments.
+- For visual changes, run `gallery/script/develop_gallery` and check the affected page on desktop, narrow viewport, and RTL when relevant.
+- If verification is skipped, state which command was skipped and why.
@@ -1,56 +1,237 @@
+import {
+  mdiAccountGroup,
+  mdiCalendarClock,
+  mdiDotsHorizontal,
+  mdiHome,
+  mdiInformationOutline,
+  mdiPalette,
+  mdiPuzzle,
+  mdiRobot,
+  mdiViewDashboard,
+} from "@mdi/js";
+
+// A group may list its pages flat in `pages`, or group them under named
+// `subsections`. The two are mutually exclusive. Listed pages keep their order;
+// any pages found in the category but not listed are appended alphabetically
+// (to a generated "Other" subsection when the group uses subsections).
 export default [
  {
    // This section has no header and so all page links are shown directly in the sidebar
    category: "concepts",
+    icon: mdiHome,
    pages: ["home"],
  },

-  {
-    category: "lovelace",
-    // Label for in the sidebar
-    header: "Dashboards",
-    // Specify order of pages. Any pages in the category folder but not listed here will
-    // automatically be added after the pages listed here.
-    pages: ["introduction"],
-  },
-  {
-    category: "automation",
-    header: "Automation",
-    pages: [
-      "editor-trigger",
-      "editor-condition",
-      "editor-action",
-      "trace",
-      "trace-timeline",
-    ],
-  },
-  {
-    category: "components",
-    header: "Components",
-  },
-  {
-    category: "more-info",
-    header: "More Info dialogs",
-  },
-  {
-    category: "misc",
-    header: "Miscellaneous",
-  },
  {
    category: "brand",
+    icon: mdiPalette,
    header: "Brand",
  },
+  {
+    category: "components",
+    icon: mdiPuzzle,
+    header: "Components",
+    subsections: [
+      {
+        header: "Form and selectors",
+        pages: [
+          "ha-form",
+          "ha-selector",
+          "ha-select-box",
+          "ha-input",
+          "ha-textarea",
+        ],
+      },
+      {
+        header: "Controls and sliders",
+        pages: [
+          "ha-button",
+          "ha-control-button",
+          "ha-progress-button",
+          "ha-switch",
+          "ha-control-switch",
+          "ha-slider",
+          "ha-control-slider",
+          "ha-control-circular-slider",
+          "ha-control-number-buttons",
+          "ha-control-select",
+          "ha-control-select-menu",
+          "ha-hs-color-picker",
+        ],
+      },
+      {
+        header: "Overlays",
+        pages: [
+          "ha-dialog",
+          "ha-dialogs",
+          "ha-adaptive-dialog",
+          "ha-adaptive-popover",
+          "ha-dropdown",
+          "ha-tooltip",
+        ],
+      },
+      {
+        header: "Lists and disclosure",
+        pages: ["ha-list", "ha-expansion-panel", "ha-faded"],
+      },
+      {
+        header: "Feedback and status",
+        pages: ["ha-alert", "ha-spinner", "ha-tip", "ha-bar", "ha-gauge"],
+      },
+      {
+        header: "Labels and text",
+        pages: ["ha-badge", "ha-label-badge", "ha-chips", "ha-marquee-text"],
+      },
+    ],
+  },
+  {
+    category: "lovelace",
+    icon: mdiViewDashboard,
+    // Label for in the sidebar
+    header: "Dashboards",
+    subsections: [
+      {
+        header: "Introduction",
+        pages: ["introduction"],
+      },
+      {
+        header: "Entity cards",
+        pages: [
+          "entities-card",
+          "entity-button-card",
+          "entity-filter-card",
+          "glance-card",
+          "tile-card",
+          "area-card",
+        ],
+      },
+      {
+        header: "Picture cards",
+        pages: [
+          "picture-card",
+          "picture-elements-card",
+          "picture-entity-card",
+          "picture-glance-card",
+        ],
+      },
+      {
+        header: "Domain cards",
+        pages: [
+          "light-card",
+          "thermostat-card",
+          "alarm-panel-card",
+          "gauge-card",
+          "plant-card",
+          "map-card",
+          "media-control-card",
+          "media-player-row",
+        ],
+      },
+      {
+        header: "Layout and utility",
+        pages: [
+          "grid-and-stack-card",
+          "conditional-card",
+          "iframe-card",
+          "markdown-card",
+          "todo-list-card",
+        ],
+      },
+    ],
+  },
+  {
+    category: "more-info",
+    icon: mdiInformationOutline,
+    header: "More Info dialogs",
+    subsections: [
+      {
+        header: "Climate and water",
+        pages: ["climate", "humidifier", "water-heater", "fan"],
+      },
+      {
+        header: "Covers and access",
+        pages: ["cover", "lock", "lawn-mower", "vacuum"],
+      },
+      {
+        header: "Lighting",
+        pages: ["light", "scene"],
+      },
+      {
+        header: "Media",
+        pages: ["media-player"],
+      },
+      {
+        header: "Inputs and values",
+        pages: ["input-number", "input-text", "number", "timer"],
+      },
+      {
+        header: "System",
+        pages: ["update"],
+      },
+    ],
+  },
+  {
+    category: "automation",
+    icon: mdiRobot,
+    header: "Automation",
+    subsections: [
+      {
+        header: "Editors",
+        pages: ["editor-trigger", "editor-condition", "editor-action"],
+      },
+      {
+        header: "Descriptions",
+        pages: ["describe-trigger", "describe-condition", "describe-action"],
+      },
+      {
+        header: "Traces",
+        pages: ["trace", "trace-timeline"],
+      },
+    ],
+  },
  {
    category: "user-test",
+    icon: mdiAccountGroup,
    header: "Users",
    pages: ["user-types", "configuration-menu"],
  },
  {
    category: "date-time",
+    icon: mdiCalendarClock,
    header: "Date and Time",
+    subsections: [
+      {
+        header: "Date",
+        pages: ["date"],
+      },
+      {
+        header: "Time",
+        pages: ["time", "time-seconds", "time-weekday"],
+      },
+      {
+        header: "Combined",
+        pages: [
+          "date-time",
+          "date-time-numeric",
+          "date-time-seconds",
+          "date-time-short",
+          "date-time-short-year",
+        ],
+      },
+    ],
  },
  {
-    category: "design.home-assistant.io",
-    header: "About",
+    category: "misc",
+    icon: mdiDotsHorizontal,
+    header: "Miscellaneous",
+    pages: [
+      "entity-state",
+      "ha-markdown",
+      "integration-card",
+      "box-shadow",
+      "util-long-press",
+      "remove-delete-add-create",
+      "editing",
+    ],
  },
 ];
@@ -0,0 +1,121 @@
+import { applyThemesOnElement } from "../../../src/common/dom/apply_themes_on_element";
+import { extractVars } from "../../../src/common/style/derived-css-vars";
+import { animationStyles } from "../../../src/resources/theme/animations.globals";
+import { coreStyles } from "../../../src/resources/theme/core.globals";
+import { colorStyles } from "../../../src/resources/theme/color/color.globals";
+import { coreColorStyles } from "../../../src/resources/theme/color/core.globals";
+import { semanticColorStyles } from "../../../src/resources/theme/color/semantic.globals";
+import { waColorStyles } from "../../../src/resources/theme/color/wa.globals";
+import { mainStyles } from "../../../src/resources/theme/main.globals";
+import { semanticStyles } from "../../../src/resources/theme/semantic.globals";
+import { typographyStyles } from "../../../src/resources/theme/typography.globals";
+import { waMainStyles } from "../../../src/resources/theme/wa.globals";
+import type { HomeAssistant, ThemeSettings } from "../../../src/types";
+
+export const GALLERY_THEME_STORAGE_KEY = "gallery-theme";
+
+export const loadGalleryThemeSettings = (): ThemeSettings => {
+  const stored = localStorage.getItem(GALLERY_THEME_STORAGE_KEY);
+  if (!stored) {
+    return { theme: "default" };
+  }
+
+  try {
+    const parsed = JSON.parse(stored) as unknown;
+    const value =
+      parsed && typeof parsed === "object"
+        ? (parsed as Partial<ThemeSettings>)
+        : {};
+    return {
+      theme: "default",
+      dark: typeof value.dark === "boolean" ? value.dark : undefined,
+      primaryColor:
+        typeof value.primaryColor === "string" ? value.primaryColor : undefined,
+      accentColor:
+        typeof value.accentColor === "string" ? value.accentColor : undefined,
+    };
+  } catch (_err) {
+    return { theme: "default" };
+  }
+};
+
+const LIGHT_THEME_STYLES = [
+  coreStyles,
+  mainStyles,
+  typographyStyles,
+  semanticStyles,
+  coreColorStyles,
+  semanticColorStyles,
+  colorStyles,
+  waColorStyles,
+  waMainStyles,
+  animationStyles,
+];
+
+const LIGHT_THEME_VARIABLES = LIGHT_THEME_STYLES.reduce<Record<string, string>>(
+  (variables, style) => {
+    for (const [key, value] of Object.entries(extractVars(style))) {
+      variables[`--${key}`] = value;
+    }
+    return variables;
+  },
+  {}
+);
+
+const LIGHT_THEME_VARIABLE_KEYS = Object.keys(LIGHT_THEME_VARIABLES);
+const LIGHT_THEME_DEFAULTS_APPLIED = new WeakSet<HTMLElement>();
+
+export const effectiveGalleryDarkMode = (
+  themeSettings: ThemeSettings,
+  systemDark: boolean
+): boolean => themeSettings.dark ?? systemDark;
+
+const galleryThemes = (darkMode: boolean): HomeAssistant["themes"] => ({
+  default_theme: "default",
+  default_dark_theme: null,
+  themes: {},
+  darkMode,
+  theme: "default",
+});
+
+const applyLightThemeDefaults = (element: HTMLElement, lightMode: boolean) => {
+  if (lightMode) {
+    for (const [key, value] of Object.entries(LIGHT_THEME_VARIABLES)) {
+      element.style.setProperty(key, value);
+    }
+    LIGHT_THEME_DEFAULTS_APPLIED.add(element);
+    return;
+  }
+
+  if (!LIGHT_THEME_DEFAULTS_APPLIED.has(element)) {
+    return;
+  }
+
+  for (const key of LIGHT_THEME_VARIABLE_KEYS) {
+    element.style.removeProperty(key);
+  }
+  LIGHT_THEME_DEFAULTS_APPLIED.delete(element);
+};
+
+export const applyFlippedGalleryTheme = (
+  element: HTMLElement,
+  themeSettings: ThemeSettings,
+  systemDark: boolean
+) => {
+  const darkMode = !effectiveGalleryDarkMode(themeSettings, systemDark);
+
+  if (!darkMode) {
+    applyThemesOnElement(element, galleryThemes(false), undefined, {
+      dark: false,
+    });
+    applyLightThemeDefaults(element, true);
+  } else {
+    applyLightThemeDefaults(element, false);
+  }
+
+  applyThemesOnElement(element, galleryThemes(darkMode), "default", {
+    ...themeSettings,
+    dark: darkMode,
+  });
+  element.style.colorScheme = darkMode ? "dark" : "light";
+};
@@ -1,25 +1,83 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { PropertyValues, TemplateResult } from "lit";
 import { html, LitElement, css, nothing } from "lit";
-import { customElement, property } from "lit/decorators";
-import { applyThemesOnElement } from "../../../src/common/dom/apply_themes_on_element";
+import { customElement, property, query, state } from "lit/decorators";
 import { fireEvent } from "../../../src/common/dom/fire_event";
+import type { HASSDomEvent } from "../../../src/common/dom/fire_event";
 import "../../../src/components/ha-card";
 import "../../../src/components/ha-button";
 import type { HaButton } from "../../../src/components/ha-button";
+import type { ThemeSettings } from "../../../src/types";
+import {
+  applyFlippedGalleryTheme,
+  effectiveGalleryDarkMode,
+  loadGalleryThemeSettings,
+} from "../common/theme";
+
+const mql = matchMedia("(prefers-color-scheme: dark)");

@customElement("demo-black-white-row")
 class DemoBlackWhiteRow extends LitElement {
  // eslint-disable-next-line lit/no-native-attributes
  @property() title!: string;

-  @property() value?: any;
+  @property({ attribute: false }) value?: unknown;

  @property({ type: Boolean }) public disabled = false;

+  @state() private _themeSettings = loadGalleryThemeSettings();
+
+  @state() private _systemDark = mql.matches;
+
+  @query(".flipped") private _flipped?: HTMLElement;
+
+  connectedCallback() {
+    super.connectedCallback();
+    mql.addEventListener("change", this._systemDarkChanged);
+    window.addEventListener(
+      "theme-settings-changed",
+      this._themeSettingsChanged as EventListener
+    );
+  }
+
+  disconnectedCallback() {
+    super.disconnectedCallback();
+    mql.removeEventListener("change", this._systemDarkChanged);
+    window.removeEventListener(
+      "theme-settings-changed",
+      this._themeSettingsChanged as EventListener
+    );
+  }
+
+  protected firstUpdated(changedProperties: PropertyValues) {
+    super.firstUpdated(changedProperties);
+    this._applyFlippedTheme();
+  }
+
+  protected updated(changedProperties: PropertyValues) {
+    super.updated(changedProperties);
+
+    if (
+      changedProperties.has("_themeSettings") ||
+      changedProperties.has("_systemDark")
+    ) {
+      this._applyFlippedTheme();
+    }
+  }
+
  protected render(): TemplateResult {
+    const currentLabel = effectiveGalleryDarkMode(
+      this._themeSettings,
+      this._systemDark
+    )
+      ? "Dark mode"
+      : "Light mode";
+    const flippedLabel =
+      currentLabel === "Dark mode" ? "Light mode" : "Dark mode";
+
    return html`
      <div class="row">
-        <div class="content light">
+        <section class="content current" aria-label=${currentLabel}>
+          <h2>${currentLabel}</h2>
          <ha-card .header=${this.title}>
            <div class="card-content">
              <slot name="light"></slot>
@@ -30,8 +88,9 @@ class DemoBlackWhiteRow extends LitElement {
              </ha-button>
            </div>
          </ha-card>
-        </div>
-        <div class="content dark">
+        </section>
+        <section class="content flipped" aria-label=${flippedLabel}>
+          <h2>${flippedLabel}</h2>
          <ha-card .header=${this.title}>
            <div class="card-content">
              <slot name="dark"></slot>
@@ -45,65 +104,84 @@ class DemoBlackWhiteRow extends LitElement {
          ${this.value
            ? html`<pre>${JSON.stringify(this.value, undefined, 2)}</pre>`
            : nothing}
-        </div>
+        </section>
      </div>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
+  handleSubmit(ev: Event) {
+    const content = (ev.target as HaButton).closest(".content");
+    if (!content) {
+      return;
+    }

-  handleSubmit(ev) {
-    const content = (ev.target as HaButton).closest(".content")!;
    fireEvent(this, "submitted" as any, {
-      slot: content.classList.contains("light") ? "light" : "dark",
+      slot: content.classList.contains("current") ? "light" : "dark",
    });
  }

+  private _themeSettingsChanged = (
+    ev: HASSDomEvent<Partial<ThemeSettings>>
+  ) => {
+    this._themeSettings = {
+      ...this._themeSettings,
+      ...ev.detail,
+      theme: "default",
+    };
+  };
+
+  private _systemDarkChanged = (ev: MediaQueryListEvent) => {
+    this._systemDark = ev.matches;
+  };
+
+  private _applyFlippedTheme() {
+    if (!this._flipped) {
+      return;
+    }
+
+    applyFlippedGalleryTheme(
+      this._flipped,
+      this._themeSettings,
+      this._systemDark
+    );
+  }
+
  static styles = css`
+    :host {
+      display: block;
+      flex: 1;
+      min-block-size: 100%;
+    }
    .row {
-      display: flex;
+      display: grid;
+      grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
+      inline-size: 100%;
+      min-block-size: 100%;
    }
    .content {
-      padding: 50px 0;
+      box-sizing: border-box;
+      min-inline-size: 0;
+      padding: var(--ha-space-8);
      background-color: var(--primary-background-color);
-    }
-    .light {
-      flex: 1;
-      padding-left: 50px;
-      padding-right: 50px;
-      box-sizing: border-box;
-    }
-    .light ha-card {
-      margin-left: auto;
-    }
-    .dark {
+      color: var(--primary-text-color);
      display: flex;
-      flex: 1;
-      padding-left: 50px;
-      box-sizing: border-box;
-      flex-wrap: wrap;
+      flex-direction: column;
+      gap: var(--ha-space-4);
    }
    ha-card {
-      width: 400px;
+      width: 100%;
+    }
+    h2 {
+      margin: 0;
+      color: var(--primary-text-color);
+      font-size: var(--ha-font-size-xl);
+      font-weight: var(--ha-font-weight-medium);
+      line-height: var(--ha-line-height-normal);
    }
    pre {
-      width: 300px;
-      margin: 0 16px 0;
+      box-sizing: border-box;
+      width: 100%;
+      margin: 0;
      overflow: auto;
      color: var(--primary-text-color);
    }
@@ -112,27 +190,18 @@ class DemoBlackWhiteRow extends LitElement {
      flex-direction: row-reverse;
      border-top: none;
    }
-    @media only screen and (max-width: 1500px) {
-      .light {
-        flex: initial;
-      }
-    }
    @media only screen and (max-width: 1000px) {
-      .light,
-      .dark {
+      .row {
+        grid-template-columns: 1fr;
+      }
+      .content {
        padding: 16px;
      }
-      .row,
-      .dark {
-        flex-direction: column;
-      }
      ha-card {
-        margin: 0 auto;
        width: 100%;
-        max-width: 400px;
      }
      pre {
-        margin: 16px auto;
+        margin: 0;
      }
    }
  `;
@@ -1,6 +1,5 @@
 import { html, css, LitElement } from "lit";
-import { customElement, property, query, state } from "lit/decorators";
-import { applyThemesOnElement } from "../../../src/common/dom/apply_themes_on_element";
+import { customElement, property, state } from "lit/decorators";
 import "../../../src/components/ha-formfield";
 import "../../../src/components/ha-switch";
 import type { HomeAssistant } from "../../../src/types";
@@ -16,17 +15,12 @@ class DemoCards extends LitElement {

  @state() private _showConfig = false;

-  @query("#container") private _container!: HTMLElement;
-
  render() {
    return html`
      <ha-demo-options>
        <ha-formfield label="Show config">
          <ha-switch @change=${this._showConfigToggled}> </ha-switch>
        </ha-formfield>
-        <ha-formfield label="Dark theme">
-          <ha-switch @change=${this._darkThemeToggled}> </ha-switch>
-        </ha-formfield>
      </ha-demo-options>
      <div id="container">
        <div class="cards">
@@ -48,12 +42,6 @@ class DemoCards extends LitElement {
    this._showConfig = ev.target.checked;
  }

-  private _darkThemeToggled(ev) {
-    applyThemesOnElement(this._container, { themes: {} } as any, "default", {
-      dark: ev.target.checked,
-    });
-  }
-
  static styles = css`
    .cards {
      display: flex;
@@ -1,6 +1,5 @@
 import { LitElement, css, html } from "lit";
 import { customElement, property, state } from "lit/decorators";
-import { applyThemesOnElement } from "../../../src/common/dom/apply_themes_on_element";
 import "../../../src/components/ha-formfield";
 import "../../../src/components/ha-switch";
 import type { HomeAssistant } from "../../../src/types";
@@ -21,9 +20,6 @@ class DemoMoreInfos extends LitElement {
        <ha-formfield label="Show config">
          <ha-switch @change=${this._showConfigToggled}> </ha-switch>
        </ha-formfield>
-        <ha-formfield label="Dark theme">
-          <ha-switch @change=${this._darkThemeToggled}> </ha-switch>
-        </ha-formfield>
      </ha-demo-options>
      <div id="container">
        <div class="cards">
@@ -51,33 +47,16 @@ class DemoMoreInfos extends LitElement {
      justify-content: center;
    }
    demo-more-info {
-      margin: 16px 16px 32px;
+      margin: var(--ha-space-4) var(--ha-space-4) var(--ha-space-8);
    }
    ha-formfield {
-      margin-right: 16px;
+      margin-right: var(--ha-space-4);
    }
  `;

  private _showConfigToggled(ev) {
    this._showConfig = ev.target.checked;
  }
-
-  private _darkThemeToggled(ev) {
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector("#container"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: false,
-        theme: "default",
-      },
-      "default",
-      {
-        dark: ev.target.checked,
-      }
-    );
-  }
 }

 declare global {
@@ -0,0 +1,153 @@
+import type { PropertyValues, TemplateResult } from "lit";
+import { css, html, LitElement } from "lit";
+import { customElement, query, state } from "lit/decorators";
+import type { HASSDomEvent } from "../../../src/common/dom/fire_event";
+import type { ThemeSettings } from "../../../src/types";
+import {
+  applyFlippedGalleryTheme,
+  effectiveGalleryDarkMode,
+  loadGalleryThemeSettings,
+} from "../common/theme";
+
+const mql = matchMedia("(prefers-color-scheme: dark)");
+
+export const THEME_COMPARISON_PANELS = [
+  { slot: "current" },
+  { slot: "flipped" },
+] as const;
+
+@customElement("demo-theme-comparison")
+export class DemoThemeComparison extends LitElement {
+  @state() private _themeSettings = loadGalleryThemeSettings();
+
+  @state() private _systemDark = mql.matches;
+
+  @query(".flipped") private _flipped?: HTMLElement;
+
+  connectedCallback() {
+    super.connectedCallback();
+    mql.addEventListener("change", this._systemDarkChanged);
+    window.addEventListener(
+      "theme-settings-changed",
+      this._themeSettingsChanged as EventListener
+    );
+  }
+
+  disconnectedCallback() {
+    super.disconnectedCallback();
+    mql.removeEventListener("change", this._systemDarkChanged);
+    window.removeEventListener(
+      "theme-settings-changed",
+      this._themeSettingsChanged as EventListener
+    );
+  }
+
+  protected firstUpdated(changedProperties: PropertyValues) {
+    super.firstUpdated(changedProperties);
+    this._applyFlippedTheme();
+  }
+
+  protected updated(changedProperties: PropertyValues) {
+    super.updated(changedProperties);
+
+    if (
+      changedProperties.has("_themeSettings") ||
+      changedProperties.has("_systemDark")
+    ) {
+      this._applyFlippedTheme();
+    }
+  }
+
+  protected render(): TemplateResult {
+    const currentLabel = effectiveGalleryDarkMode(
+      this._themeSettings,
+      this._systemDark
+    )
+      ? "Dark mode"
+      : "Light mode";
+    const flippedLabel =
+      currentLabel === "Dark mode" ? "Light mode" : "Dark mode";
+
+    return html`
+      <section class="panel" aria-label=${currentLabel}>
+        <h2>${currentLabel}</h2>
+        <slot name="current"></slot>
+      </section>
+      <section class="panel flipped" aria-label=${flippedLabel}>
+        <h2>${flippedLabel}</h2>
+        <slot name="flipped"></slot>
+      </section>
+    `;
+  }
+
+  private _themeSettingsChanged = (
+    ev: HASSDomEvent<Partial<ThemeSettings>>
+  ) => {
+    this._themeSettings = {
+      ...this._themeSettings,
+      ...ev.detail,
+      theme: "default",
+    };
+  };
+
+  private _systemDarkChanged = (ev: MediaQueryListEvent) => {
+    this._systemDark = ev.matches;
+  };
+
+  private _applyFlippedTheme() {
+    if (!this._flipped) {
+      return;
+    }
+
+    applyFlippedGalleryTheme(
+      this._flipped,
+      this._themeSettings,
+      this._systemDark
+    );
+  }
+
+  static styles = css`
+    :host {
+      box-sizing: border-box;
+      display: grid;
+      flex: 1;
+      grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
+      inline-size: 100%;
+      min-block-size: 100%;
+    }
+
+    .panel {
+      box-sizing: border-box;
+      min-block-size: 100%;
+      min-inline-size: 0;
+      padding: var(--ha-space-6);
+      background-color: var(--primary-background-color);
+      color: var(--primary-text-color);
+    }
+
+    h2 {
+      margin: 0 0 var(--ha-space-4);
+      color: var(--primary-text-color);
+      font-size: var(--ha-font-size-xl);
+      font-weight: var(--ha-font-weight-medium);
+      line-height: var(--ha-line-height-normal);
+    }
+
+    ::slotted(*) {
+      box-sizing: border-box;
+      inline-size: 100%;
+    }
+
+    @media only screen and (max-width: 1000px) {
+      :host {
+        grid-template-columns: 1fr;
+      }
+    }
+  `;
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    "demo-theme-comparison": DemoThemeComparison;
+  }
+}
@@ -0,0 +1,87 @@
+import { css, html, LitElement } from "lit";
+import { customElement, property } from "lit/decorators";
+import { fireEvent } from "../../../src/common/dom/fire_event";
+import "../../../src/components/ha-card";
+import "../../../src/components/ha-settings-row";
+import "../../../src/components/ha-switch";
+import type { HaSwitch } from "../../../src/components/ha-switch";
+import "../../../src/components/ha-theme-settings";
+import type { HomeAssistant, ThemeSettings } from "../../../src/types";
+
+@customElement("gallery-settings")
+class GallerySettings extends LitElement {
+  @property({ attribute: false }) public hass!: HomeAssistant;
+
+  @property({ attribute: false }) public themeSettings!: ThemeSettings;
+
+  @property({ type: Boolean }) public narrow = false;
+
+  @property({ type: Boolean }) public rtl = false;
+
+  protected render() {
+    return html`
+      <div class="content">
+        <ha-card .header=${"Appearance"}>
+          <div class="card-content">
+            Configure how the gallery renders component previews and examples.
+          </div>
+          <ha-theme-settings
+            .hass=${this.hass}
+            .selectedTheme=${this.themeSettings}
+            .narrow=${this.narrow}
+            .heading=${"Theme"}
+            .description=${"Choose the mode and colors used throughout the gallery."}
+            .labels=${{
+              mode: "Theme mode",
+              autoMode: "Auto",
+              lightMode: "Light",
+              darkMode: "Dark",
+              primaryColor: "Primary color",
+              accentColor: "Accent color",
+              reset: "Reset",
+            }}
+            .showThemePicker=${false}
+          ></ha-theme-settings>
+          <ha-settings-row .narrow=${this.narrow}>
+            <span slot="heading">Right-to-left layout</span>
+            <span slot="description">
+              Preview the gallery with right-to-left text direction.
+            </span>
+            <ha-switch
+              .checked=${this.rtl}
+              @change=${this._rtlChanged}
+            ></ha-switch>
+          </ha-settings-row>
+        </ha-card>
+      </div>
+    `;
+  }
+
+  private _rtlChanged(ev: Event) {
+    fireEvent(this, "gallery-rtl-changed", {
+      rtl: (ev.currentTarget as HaSwitch).checked,
+    });
+  }
+
+  static styles = css`
+    .content {
+      max-width: 800px;
+      margin: 0 auto;
+      padding: var(--ha-space-4);
+    }
+
+    ha-card {
+      overflow: hidden;
+    }
+  `;
+}
+
+declare global {
+  interface HASSDomEvents {
+    "gallery-rtl-changed": { rtl: boolean };
+  }
+
+  interface HTMLElementTagNameMap {
+    "gallery-settings": GallerySettings;
+  }
+}
@@ -13,13 +13,10 @@ class PageDescription extends HaMarkdown {
      return nothing;
    }

+    const subtitle = PAGES[this.page].metadata.subtitle;
+
    return html`
-      <div class="heading">
-        <div class="title">
-          ${PAGES[this.page].metadata.title || this.page.split("/")[1]}
-        </div>
-        <div class="subtitle">${PAGES[this.page].metadata.subtitle}</div>
-      </div>
+      ${subtitle ? html`<div class="subtitle">${subtitle}</div>` : nothing}
      ${until(
        PAGES[this.page]
          .description()
@@ -32,16 +29,9 @@ class PageDescription extends HaMarkdown {
  static styles = [
    HaMarkdown.styles,
    css`
-      .heading {
+      .subtitle {
        padding: 16px;
        border-bottom: 1px solid var(--secondary-background-color);
-      }
-      .title {
-        font-size: 42px;
-        line-height: var(--ha-line-height-condensed);
-        padding-bottom: 8px;
-      }
-      .subtitle {
        font-size: var(--ha-font-size-l);
        line-height: var(--ha-line-height-normal);
      }
@@ -16,22 +16,9 @@ class HaDemoOptions extends LitElement {
    css`
      :host {
        display: block;
-        background-color: var(--light-primary-color);
-        margin-left: 60px
-        margin-right: 60px;
-        display: var(--layout-horizontal_-_display);
-        -ms-flex-direction: var(--layout-horizontal_-_-ms-flex-direction);
-        -webkit-flex-direction: var(
-          --layout-horizontal_-_-webkit-flex-direction
-        );
-        flex-direction: var(--layout-horizontal_-_flex-direction);
-        -ms-flex-align: var(--layout-center_-_-ms-flex-align);
-        -webkit-align-items: var(--layout-center_-_-webkit-align-items);
-        align-items: var(--layout-center_-_align-items);
+        background-color: var(--primary-background-color);
        position: relative;
-        height: 64px;
-        padding: 0 16px;
-        pointer-events: none;
+        padding: var(--ha-space-2) var(--ha-space-16) var(--ha-space-1);
        font-size: var(--ha-font-size-xl);
      }
    `,
@@ -1,161 +1,194 @@
-import { mdiMenu, mdiSwapHorizontal } from "@mdi/js";
+import { mdiCog, mdiMenu } from "@mdi/js";
+import type { Connection } from "home-assistant-js-websocket";
 import type { PropertyValues } from "lit";
-import { LitElement, css, html } from "lit";
+import { LitElement, css, html, nothing } from "lit";
 import { customElement, query, state } from "lit/decorators";
+import { classMap } from "lit/directives/class-map";
+import { ifDefined } from "lit/directives/if-defined";
+import { applyThemesOnElement } from "../../src/common/dom/apply_themes_on_element";
 import { dynamicElement } from "../../src/common/dom/dynamic-element-directive";
+import type { HASSDomEvent } from "../../src/common/dom/fire_event";
 import { setDirectionStyles } from "../../src/common/util/compute_rtl";
 import "../../src/components/ha-button";
 import "../../src/components/ha-drawer";
-import type { HaDrawer } from "../../src/components/ha-drawer";
 import { HaExpansionPanel } from "../../src/components/ha-expansion-panel";
 import "../../src/components/ha-icon-button";
+import "../../src/components/ha-sidebar";
+import "../../src/components/item/ha-list-item-button";
 import "../../src/components/ha-svg-icon";
 import "../../src/components/ha-top-app-bar-fixed";
 import "../../src/managers/notification-manager";
 import { haStyle } from "../../src/resources/styles";
+import type { HomeAssistant, ThemeSettings } from "../../src/types";
 import { PAGES, SIDEBAR } from "../build/import-pages";
+import {
+  GALLERY_THEME_STORAGE_KEY,
+  loadGalleryThemeSettings,
+} from "./common/theme";
+import "./components/gallery-settings";
 import "./components/page-description";

 const RTL_STORAGE_KEY = "gallery-rtl";
+const SETTINGS_PAGE = "settings";

 const GITHUB_DEMO_URL =
  "https://github.com/home-assistant/frontend/blob/dev/gallery/src/pages/";

-const FAKE_HASS = {
-  // Just enough for computeRTL for notification-manager
-  language: "en",
-  translationMetadata: {
-    translations: {},
+interface GalleryPage {
+  metadata: Record<string, unknown>;
+  description?: unknown;
+  demo?: unknown;
+}
+
+interface GallerySidebarSubsection {
+  header: string;
+  pages: string[];
+}
+
+interface GallerySidebarGroup {
+  category: string;
+  header?: string;
+  icon?: string;
+  pages?: string[];
+  subsections?: GallerySidebarSubsection[];
+}
+
+const groupPages = (group: GallerySidebarGroup): string[] =>
+  group.subsections
+    ? group.subsections.flatMap((subsection) => subsection.pages)
+    : (group.pages ?? []);
+
+const GALLERY_SIDEBAR = SIDEBAR as GallerySidebarGroup[];
+const DEFAULT_PAGE = `${GALLERY_SIDEBAR[0].category}/${groupPages(GALLERY_SIDEBAR[0])[0]}`;
+
+const mql = matchMedia("(prefers-color-scheme: dark)");
+
+const galleryLocalize = (key: string) =>
+  (
+    ({
+      "ui.sidebar.sidebar_toggle": "Toggle sidebar",
+      "ui.notification_drawer.title": "Notifications",
+      "ui.sidebar.external_app_configuration": "App configuration",
+      "panel.config": "Settings",
+    }) as Record<string, string>
+  )[key] ?? key;
+
+const galleryConnection = {
+  subscribeMessage(
+    callback: (message: unknown) => void,
+    message: { type?: string }
+  ) {
+    if (message.type === "frontend/subscribe_user_data") {
+      callback({ value: { panelOrder: [], hiddenPanels: [] } });
+    } else if (message.type === "persistent_notification/subscribe") {
+      callback({ type: "current", notifications: {} });
+    }
+    return Promise.resolve(() => undefined);
  },
-};
+  sendMessagePromise() {
+    return Promise.resolve({ value: null });
+  },
+} as unknown as Connection;

@customElement("ha-gallery")
 class HaGallery extends LitElement {
-  @state() private _page =
-    document.location.hash.substring(1) ||
-    `${SIDEBAR[0].category}/${SIDEBAR[0].pages![0]}`;
+  @state() private _page = this._pageFromLocation();

  @state() private _rtl = localStorage.getItem(RTL_STORAGE_KEY) === "true";

+  @state() private _themeSettings = loadGalleryThemeSettings();
+
+  @state() private _systemDark = mql.matches;
+
  @query("notification-manager")
  private _notifications!: HTMLElementTagNameMap["notification-manager"];

-  @query("ha-drawer")
-  private _drawer!: HaDrawer;
+  @query("ha-sidebar")
+  private _sidebar?: HTMLElementTagNameMap["ha-sidebar"];
+
+  @query(".gallery-nav-item[selected]")
+  private _selectedNavigationItem?: HTMLElementTagNameMap["ha-list-item-button"];

  private _narrow = window.matchMedia("(max-width: 600px)").matches;

+  @state() private _drawerOpen = !this._narrow;
+
  render() {
-    const sidebar: unknown[] = [];
-
-    for (const group of SIDEBAR) {
-      const links: unknown[] = [];
-
-      for (const page of group.pages!) {
-        const key = `${group.category}/${page}`;
-        const active = this._page === key;
-        if (!(key in PAGES)) {
-          console.error("Undefined page referenced in sidebar.js:", key);
-          continue;
-        }
-        const title = PAGES[key].metadata.title || page;
-        links.push(html`
-          <a ?active=${active} href=${`#${group.category}/${page}`}>${title}</a>
-        `);
-      }
-
-      sidebar.push(
-        group.header
-          ? html`
-              <ha-expansion-panel .header=${group.header}>
-                ${links}
-              </ha-expansion-panel>
-            `
-          : links
-      );
-    }
+    const isSettingsPage = this._page === SETTINGS_PAGE;
+    const page = isSettingsPage ? undefined : PAGES[this._page];

    return html`
      <ha-drawer
        .direction=${this._rtl ? "rtl" : "ltr"}
-        .open=${!this._narrow}
+        .open=${this._drawerOpen}
        .type=${this._narrow ? "modal" : "dismissible"}
      >
-        <div class="drawer-title">Home Assistant Design</div>
-        <div class="sidebar">${sidebar}</div>
+        <ha-sidebar
+          .hass=${this._galleryHass}
+          .narrow=${this._narrow}
+          .route=${{ prefix: "", path: this._page }}
+          .alwaysExpand=${true}
+          sidebar-title="Home Assistant Design"
+          @hass-toggle-menu=${this._toggleDrawer}
+        >
+          ${this._renderSidebarNavigation()} ${this._renderSettingsItem()}
+        </ha-sidebar>
        <div slot="appContent" class="app-content">
-          <ha-top-app-bar-fixed>
-            <ha-icon-button
-              slot="navigationIcon"
-              @click=${this._menuTapped}
-              .path=${mdiMenu}
-            ></ha-icon-button>
+          <ha-top-app-bar-fixed .narrow=${this._narrow}>
+            ${this._narrow || !this._drawerOpen
+              ? html`<ha-icon-button
+                  slot="navigationIcon"
+                  @click=${this._toggleDrawer}
+                  .path=${mdiMenu}
+                ></ha-icon-button>`
+              : nothing}

            <div slot="title">
-              ${PAGES[this._page].metadata.title || this._page.split("/")[1]}
+              ${isSettingsPage
+                ? "Settings"
+                : page?.metadata.title || this._page.split("/")[1]}
            </div>
+            <div class="content">
+              ${isSettingsPage
+                ? html`<gallery-settings
+                    .hass=${this._galleryHass}
+                    .themeSettings=${this._themeSettings}
+                    .narrow=${this._narrow}
+                    .rtl=${this._rtl}
+                    @theme-settings-changed=${this._themeSettingsChanged}
+                    @gallery-rtl-changed=${this._rtlChanged}
+                  ></gallery-settings>`
+                : html`
+                    ${page?.description
+                      ? html`
+                          <page-description .page=${this._page}>
+                          </page-description>
+                        `
+                      : nothing}
+                    ${dynamicElement(`demo-${this._page.replace("/", "-")}`)}
+                  `}
+            </div>
+            ${isSettingsPage || !page ? nothing : this._renderPageFooter(page)}
          </ha-top-app-bar-fixed>
-          <div class="content">
-            ${PAGES[this._page].description
-              ? html`
-                  <page-description .page=${this._page}></page-description>
-                `
-              : ""}
-            ${dynamicElement(`demo-${this._page.replace("/", "-")}`)}
-          </div>
-          <div class="page-footer">
-            <div class="edit-docs">
-              <div class="header">Help us to improve our documentation</div>
-              <div class="secondary">
-                Suggest an edit to this page, or provide/view feedback for this
-                page.
-              </div>
-              <div>
-                ${PAGES[this._page].description ||
-                Object.keys(PAGES[this._page].metadata).length > 0
-                  ? html`
-                      <a
-                        href=${`${GITHUB_DEMO_URL}${this._page}.markdown`}
-                        target="_blank"
-                      >
-                        Edit text
-                      </a>
-                    `
-                  : ""}
-                ${PAGES[this._page].demo
-                  ? html`
-                      <a
-                        href=${`${GITHUB_DEMO_URL}${this._page}.ts`}
-                        target="_blank"
-                      >
-                        Edit demo
-                      </a>
-                    `
-                  : ""}
-              </div>
-            </div>
-            <div class="rtl-toggle">
-              <ha-icon-button
-                @click=${this._toggleRtl}
-                .label=${this._rtl ? "Switch to LTR" : "Switch to RTL"}
-              >
-                <ha-svg-icon .path=${mdiSwapHorizontal}></ha-svg-icon>
-              </ha-icon-button>
-            </div>
-          </div>
        </div>
      </ha-drawer>
      <notification-manager
-        .hass=${FAKE_HASS}
+        .hass=${this._galleryHass}
        id="notifications"
      ></notification-manager>
    `;
  }

+  connectedCallback() {
+    super.connectedCallback();
+    mql.addEventListener("change", this._systemDarkChanged);
+  }
+
  firstUpdated(changedProps: PropertyValues<this>) {
    super.firstUpdated(changedProps);

    this._applyDirection();
+    this._applyTheme();

    this.addEventListener("show-notification", (ev) =>
      this._notifications.showDialog({ message: ev.detail.message })
@@ -171,16 +204,26 @@ class HaGallery extends LitElement {
      }
    });

-    document.location.hash = this._page;
+    if (document.location.hash.substring(1) !== this._page) {
+      document.location.hash = this._page;
+    }

-    window.addEventListener("hashchange", () => {
-      this._page = document.location.hash.substring(1);
-      if (this._narrow) {
-        this._drawer.open = false;
-      }
-    });
+    window.addEventListener("hashchange", this._hashChanged);
  }

+  disconnectedCallback() {
+    super.disconnectedCallback();
+    mql.removeEventListener("change", this._systemDarkChanged);
+    window.removeEventListener("hashchange", this._hashChanged);
+  }
+
+  private _hashChanged = () => {
+    this._page = this._pageFromLocation();
+    if (this._narrow) {
+      this._drawerOpen = false;
+    }
+  };
+
  updated(changedProps: PropertyValues) {
    super.updated(changedProps);

@@ -188,37 +231,354 @@ class HaGallery extends LitElement {
      this._applyDirection();
    }

+    if (changedProps.has("_themeSettings") || changedProps.has("_systemDark")) {
+      this._applyTheme();
+    }
+
    if (!changedProps.has("_page")) {
      return;
    }

+    if (this._page === SETTINGS_PAGE) {
+      return;
+    }
+
    if (PAGES[this._page].demo) {
      PAGES[this._page].demo();
    }

-    const menuItem = this.shadowRoot!.querySelector(
-      `a[href="#${this._page}"]`
-    )!;
+    void this._scrollSelectedNavigationItemIntoView();
+  }

-    // Make sure section is expanded
+  private async _scrollSelectedNavigationItemIntoView() {
+    const menuItem = this._selectedNavigationItem;
+
+    if (!menuItem) {
+      return;
+    }
+
+    // Make sure section is expanded before measuring the selected item.
    if (menuItem.parentElement instanceof HaExpansionPanel) {
      menuItem.parentElement.expanded = true;
+      await menuItem.parentElement.updateComplete;
    }
+
+    const scrollable = this._sidebar?.shadowRoot?.querySelector<HTMLElement>(
+      "ha-list-nav.before-spacer"
+    );
+
+    if (!scrollable) {
+      return;
+    }
+
+    requestAnimationFrame(() => {
+      const itemRect = menuItem.getBoundingClientRect();
+      const scrollableRect = scrollable.getBoundingClientRect();
+      const targetScrollTop =
+        scrollable.scrollTop +
+        itemRect.top -
+        scrollableRect.top -
+        (scrollableRect.height - itemRect.height) / 2;
+
+      scrollable.scrollTo({
+        top: Math.min(
+          Math.max(0, targetScrollTop),
+          scrollable.scrollHeight - scrollable.clientHeight
+        ),
+        left: 0,
+      });
+      scrollable.scrollLeft = 0;
+    });
  }

-  private _menuTapped() {
-    this._drawer.open = !this._drawer.open;
+  private _renderSidebarNavigation() {
+    const sidebar: unknown[] = [];
+
+    for (const group of GALLERY_SIDEBAR) {
+      const expanded = groupPages(group).some(
+        (page) => this._page === `${group.category}/${page}`
+      );
+
+      const content = group.subsections
+        ? group.subsections.map((subsection) =>
+            this._renderSidebarSubsection(group, subsection)
+          )
+        : this._renderPageLinks(group, group.pages ?? []);
+
+      sidebar.push(
+        group.header
+          ? html`
+              <ha-expansion-panel
+                slot="main-navigation"
+                class="gallery-sidebar-section"
+                .header=${group.header}
+                ?expanded=${expanded}
+              >
+                ${group.icon
+                  ? html`<ha-svg-icon
+                      slot="leading-icon"
+                      class="gallery-sidebar-icon"
+                      .path=${group.icon}
+                    ></ha-svg-icon>`
+                  : nothing}
+                ${content}
+              </ha-expansion-panel>
+            `
+          : content
+      );
+    }
+
+    return sidebar;
  }

-  private _toggleRtl() {
-    this._rtl = !this._rtl;
-    localStorage.setItem(RTL_STORAGE_KEY, String(this._rtl));
+  private _renderSidebarSubsection(
+    group: GallerySidebarGroup,
+    subsection: GallerySidebarSubsection
+  ) {
+    return html`
+      <div class="gallery-sidebar-subheader">${subsection.header}</div>
+      ${this._renderPageLinks(group, subsection.pages)}
+    `;
+  }
+
+  private _renderPageLinks(group: GallerySidebarGroup, pages: string[]) {
+    const links: unknown[] = [];
+    for (const page of pages) {
+      const key = `${group.category}/${page}`;
+      if (!(key in PAGES)) {
+        console.error("Undefined page referenced in sidebar.js:", key);
+        continue;
+      }
+      links.push(
+        this._renderPageLink(
+          key,
+          PAGES[key].metadata.title || page,
+          group.header ? undefined : "main-navigation",
+          group.header ? undefined : group.icon
+        )
+      );
+    }
+    return links;
+  }
+
+  private _renderPageLink(
+    page: string,
+    title: string,
+    slot?: string,
+    iconPath?: string
+  ) {
+    return html`
+      <ha-list-item-button
+        slot=${ifDefined(slot)}
+        class=${classMap({
+          "gallery-nav-item": true,
+          "has-icon": Boolean(iconPath),
+          selected: this._page === page,
+        })}
+        ?selected=${this._page === page}
+        href=${`#${page}`}
+      >
+        ${iconPath
+          ? html`<ha-svg-icon slot="start" .path=${iconPath}></ha-svg-icon>`
+          : nothing}
+        <span slot="headline">${title}</span>
+      </ha-list-item-button>
+    `;
+  }
+
+  private _renderSettingsItem() {
+    return html`
+      <ha-list-item-button
+        slot="fixed-navigation"
+        class=${classMap({
+          "gallery-settings-item": true,
+          selected: this._page === SETTINGS_PAGE,
+        })}
+        ?selected=${this._page === SETTINGS_PAGE}
+        href="#settings"
+      >
+        <ha-svg-icon slot="start" .path=${mdiCog}></ha-svg-icon>
+        <span slot="headline">Settings</span>
+      </ha-list-item-button>
+    `;
+  }
+
+  private _renderPageFooter(page: GalleryPage) {
+    return html`<div class="page-footer">
+      <div class="edit-docs">
+        <div class="header">Help us to improve our documentation</div>
+        <div class="secondary">
+          Suggest an edit to this page, or provide/view feedback for this page.
+        </div>
+        <div>
+          ${page.description || Object.keys(page.metadata).length > 0
+            ? html`
+                <a
+                  href=${`${GITHUB_DEMO_URL}${this._page}.markdown`}
+                  target="_blank"
+                >
+                  Edit text
+                </a>
+              `
+            : nothing}
+          ${page.demo
+            ? html`
+                <a href=${`${GITHUB_DEMO_URL}${this._page}.ts`} target="_blank">
+                  Edit demo
+                </a>
+              `
+            : nothing}
+        </div>
+      </div>
+    </div>`;
+  }
+
+  private _toggleDrawer(ev?: Event) {
+    ev?.stopPropagation();
+    this._drawerOpen = !this._drawerOpen;
  }

  private _applyDirection() {
    setDirectionStyles(this._rtl ? "rtl" : "ltr", this);
  }

+  private _themeSettingsChanged(ev: HASSDomEvent<Partial<ThemeSettings>>) {
+    this._themeSettings = {
+      ...this._themeSettings,
+      ...ev.detail,
+      theme: "default",
+    };
+    localStorage.setItem(
+      GALLERY_THEME_STORAGE_KEY,
+      JSON.stringify(this._themeSettings)
+    );
+  }
+
+  private _rtlChanged(ev: HASSDomEvent<{ rtl: boolean }>) {
+    this._rtl = ev.detail.rtl;
+    localStorage.setItem(RTL_STORAGE_KEY, String(this._rtl));
+  }
+
+  private _systemDarkChanged = (ev: MediaQueryListEvent) => {
+    this._systemDark = ev.matches;
+  };
+
+  private _applyTheme() {
+    applyThemesOnElement(
+      document.documentElement,
+      this._themes,
+      "default",
+      this._themeSettings,
+      true
+    );
+
+    let schemeMeta = document.querySelector("meta[name=color-scheme]");
+    if (!schemeMeta) {
+      schemeMeta = document.createElement("meta");
+      schemeMeta.setAttribute("name", "color-scheme");
+      document.head.appendChild(schemeMeta);
+    }
+    schemeMeta.setAttribute(
+      "content",
+      this._effectiveDarkMode ? "dark" : "light"
+    );
+    document.documentElement.style.colorScheme = this._effectiveDarkMode
+      ? "dark"
+      : "light";
+
+    const themeMeta = document.querySelector("meta[name=theme-color]");
+    if (themeMeta) {
+      if (!themeMeta.hasAttribute("default-content")) {
+        themeMeta.setAttribute(
+          "default-content",
+          themeMeta.getAttribute("content") ?? ""
+        );
+      }
+      const styles = getComputedStyle(document.documentElement);
+      const themeColor =
+        styles.getPropertyValue("--app-theme-color").trim() ||
+        styles.getPropertyValue("--primary-background-color").trim() ||
+        themeMeta.getAttribute("default-content") ||
+        "";
+      themeMeta.setAttribute("content", themeColor);
+    }
+  }
+
+  private _pageFromLocation() {
+    const page = document.location.hash.substring(1);
+    return page === SETTINGS_PAGE || page in PAGES ? page : DEFAULT_PAGE;
+  }
+
+  private get _effectiveDarkMode() {
+    return this._themeSettings.dark ?? this._systemDark;
+  }
+
+  private get _themes(): HomeAssistant["themes"] {
+    return {
+      default_theme: "default",
+      default_dark_theme: null,
+      themes: {},
+      darkMode: this._effectiveDarkMode,
+      theme: "default",
+    };
+  }
+
+  private get _galleryHass(): HomeAssistant {
+    return {
+      auth: {},
+      areas: {},
+      config: {},
+      connected: true,
+      connection: galleryConnection,
+      debugConnection: false,
+      devices: {},
+      dockedSidebar: "docked",
+      enableShortcuts: true,
+      entities: {},
+      floors: {},
+      hassUrl: (path) => path,
+      kioskMode: false,
+      language: "en",
+      loadBackendTranslation: async () => galleryLocalize,
+      loadFragmentTranslation: async () => undefined,
+      locale: {
+        language: "en",
+        number_format: "language",
+        time_format: "language",
+        date_format: "language",
+        first_weekday: "language",
+        time_zone: "local",
+      },
+      localize: galleryLocalize,
+      panelUrl: this._page,
+      panels: {},
+      selectedLanguage: null,
+      selectedTheme: this._themeSettings,
+      services: {},
+      states: {},
+      suspendWhenHidden: false,
+      systemData: {},
+      themes: this._themes,
+      translationMetadata: { fragments: [], translations: {} },
+      user: {
+        id: "gallery",
+        is_admin: false,
+        is_owner: false,
+        name: "Settings",
+        credentials: [],
+        mfa_modules: [],
+      },
+      userData: {},
+      vibrate: false,
+      callApi: async () => undefined,
+      callApiRaw: async () => new Response(),
+      callService: async () => ({ context: { id: "gallery" } }),
+      callWS: async () => undefined,
+      fetchWithAuth: async () => new Response(),
+      sendWS: () => undefined,
+    } as unknown as HomeAssistant;
+  }
+
  static styles = [
    haStyle,
    css`
@@ -226,49 +586,113 @@ class HaGallery extends LitElement {
        -ms-user-select: initial;
        -webkit-user-select: initial;
        -moz-user-select: initial;
-        --ha-sidebar-width: 256px;
-        --header-height: 64px;
+        --ha-sidebar-width: 300px;
+        --ha-sidebar-expanded-width: 300px;
+        --ha-sidebar-expanded-item-width: 292px;
+        --ha-sidebar-expanded-section-item-width: 256px;
+        --app-header-background-color: var(--sidebar-background-color);
+        --app-header-text-color: var(--sidebar-text-color);
+        --app-header-border-bottom: 1px solid var(--divider-color);
      }

-      .sidebar {
+      .gallery-sidebar-section {
+        color: var(--sidebar-text-color);
        box-sizing: border-box;
-        max-height: calc(100vh - var(--header-height));
-        overflow-y: auto;
-        padding: 4px;
+        margin: 0 var(--ha-space-1) var(--ha-space-1);
+        overflow-x: hidden;
+        border-radius: var(--ha-border-radius-sm);
+        --expansion-panel-summary-padding: 0 var(--ha-space-2);
      }

-      .drawer-title {
-        align-items: center;
+      .gallery-sidebar-section::part(summary) {
+        min-height: var(--ha-space-10);
+        border-radius: var(--ha-border-radius-sm);
        box-sizing: border-box;
-        color: var(--primary-text-color);
-        display: flex;
-        font-size: var(--ha-font-size-l);
+      }
+
+      .gallery-sidebar-section .gallery-nav-item {
+        margin-inline-start: var(--ha-space-4);
+        width: var(--ha-sidebar-expanded-section-item-width, 248px);
+      }
+
+      .gallery-sidebar-subheader {
+        margin: var(--ha-space-2) var(--ha-space-4) var(--ha-space-1);
+        color: var(--secondary-text-color);
+        font-size: var(--ha-font-size-s);
        font-weight: var(--ha-font-weight-medium);
-        min-height: var(--header-height);
-        padding: 0 16px;
+        line-height: var(--ha-line-height-condensed);
+        text-transform: uppercase;
+        letter-spacing: 0.04em;
      }

-      .sidebar a {
-        color: var(--primary-text-color);
-        display: block;
-        padding: 12px;
-        text-decoration: none;
+      .gallery-sidebar-icon,
+      .gallery-nav-item ha-svg-icon[slot="start"] {
+        color: var(--sidebar-icon-color);
+        flex-shrink: 0;
+        height: var(--ha-space-6);
+        width: var(--ha-space-6);
+      }
+
+      .gallery-sidebar-icon {
+        margin-inline-end: var(--ha-space-3);
+      }
+
+      .gallery-nav-item,
+      .gallery-settings-item {
+        flex-shrink: 0;
+        margin: 0 var(--ha-space-1) var(--ha-space-1);
+        border-radius: var(--ha-border-radius-sm);
+        --ha-row-item-min-height: var(--ha-space-10);
+        --ha-row-item-padding-block: 0;
+        --ha-row-item-padding-inline: var(--ha-space-3);
        position: relative;
+        width: var(--ha-sidebar-expanded-item-width, 248px);
+        color: var(--sidebar-text-color);
      }

-      .sidebar a[active]::before {
-        border-radius: var(--ha-border-radius-lg);
+      .gallery-nav-item.has-icon,
+      .gallery-settings-item {
+        --ha-row-item-gap: var(--ha-space-3);
+        --ha-row-item-padding-inline: var(--ha-space-2) var(--ha-space-3);
+      }
+
+      .gallery-nav-item::part(headline),
+      .gallery-settings-item::part(headline) {
+        color: inherit;
+      }
+
+      .gallery-nav-item[selected],
+      .gallery-settings-item[selected] {
+        color: var(--sidebar-selected-icon-color);
+      }
+
+      .gallery-nav-item[selected]::before,
+      .gallery-settings-item[selected]::before {
+        border-radius: var(--ha-border-radius-sm);
        position: absolute;
        top: 0;
-        right: 2px;
+        right: 0;
        bottom: 0;
-        left: 2px;
+        left: 0;
        pointer-events: none;
        content: "";
-        transition: opacity 15ms linear;
-        will-change: opacity;
        background-color: var(--sidebar-selected-icon-color);
-        opacity: 0.12;
+        opacity: var(--dark-divider-opacity);
+      }
+
+      .gallery-settings-item ha-svg-icon[slot="start"] {
+        color: var(--sidebar-icon-color);
+        flex-shrink: 0;
+        height: var(--ha-space-6);
+        width: var(--ha-space-6);
+      }
+
+      .gallery-settings-item[selected] ha-svg-icon[slot="start"] {
+        color: var(--sidebar-selected-icon-color);
+      }
+
+      .gallery-nav-item[selected] ha-svg-icon[slot="start"] {
+        color: var(--sidebar-selected-icon-color);
      }

      .app-content {
@@ -283,11 +707,16 @@ class HaGallery extends LitElement {
      }

      .content {
+        box-sizing: border-box;
+        display: flex;
+        flex-direction: column;
        flex: 1;
+        padding-top: var(--ha-space-4);
      }

      page-description {
-        margin: 16px;
+        display: block;
+        margin: 0 var(--ha-space-4) var(--ha-space-4);
      }

      .page-footer {
@@ -324,18 +753,6 @@ class HaGallery extends LitElement {
        margin: 0 8px;
        text-decoration: none;
      }
-
-      .rtl-toggle {
-        padding: var(--ha-space-4);
-        display: inline-flex;
-        align-items: flex-end;
-        margin-top: 12px !important;
-      }
-
-      .rtl-toggle ha-icon-button {
-        border: 1px solid var(--divider-color);
-        border-radius: var(--ha-border-radius-pill);
-      }
    `,
  ];
 }
@@ -1,11 +1,11 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-alert";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-button";
 import "../../../../src/components/ha-logo-svg";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const alerts: {
  title?: string;
@@ -135,10 +135,10 @@ const alerts: {
 export class DemoHaAlert extends LitElement {
  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-alert ${mode} demo">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                ${alerts.map(
                  (alert) => html`
@@ -154,43 +154,19 @@ export class DemoHaAlert extends LitElement {
                )}
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      flex-direction: row;
-      justify-content: space-between;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    ha-alert {
      display: block;
@@ -1,12 +1,12 @@
 import { mdiButtonCursor, mdiHome } from "@mdi/js";
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-badge";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-svg-icon";
 import { mdiHomeAssistant } from "../../../../src/resources/home-assistant-logo-svg";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const badges: {
  type?: "badge" | "button";
@@ -60,10 +60,10 @@ const badges: {
 export class DemoHaBadge extends LitElement {
  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-badge ${mode} demo">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                ${badges.map(
                  (badge) => html`
@@ -78,45 +78,23 @@ export class DemoHaBadge extends LitElement {
                )}
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
+      flex-wrap: wrap;
      gap: var(--ha-space-6);
    }
  `;
@@ -1,13 +1,13 @@
 import { mdiHome } from "@mdi/js";
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import { titleCase } from "../../../../src/common/string/title-case";
 import "../../../../src/components/ha-button";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-svg-icon";
 import { mdiHomeAssistant } from "../../../../src/resources/home-assistant-logo-svg";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const appearances = ["accent", "filled", "plain"];
 const variants = ["brand", "danger", "neutral", "warning", "success"];
@@ -16,10 +16,10 @@ const variants = ["brand", "danger", "neutral", "warning", "success"];
 export class DemoHaButton extends LitElement {
  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-button in ${mode}">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                ${variants.map(
                  (variant) => html`
@@ -112,45 +112,22 @@ export class DemoHaButton extends LitElement {
                )}
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    .button {
      padding: unset;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -159,6 +136,7 @@ export class DemoHaButton extends LitElement {
    }
    .card-content div {
      display: flex;
+      flex-wrap: wrap;
      gap: var(--ha-space-2);
    }
  `;
@@ -26,7 +26,7 @@ const chips: {
 export class DemoHaChips extends LitElement {
  protected render(): TemplateResult {
    return html`
-      <ha-card header="ha-chip demo">
+      <ha-card>
        <div class="card-content">
          <p>Action chip</p>
          <ha-chip-set>
@@ -82,7 +82,7 @@ export class DemoHaChips extends LitElement {
                  ${chip.icon
                    ? html`<ha-svg-icon slot="icon" .path=${chip.icon}>
                      </ha-svg-icon>`
-                    : ""}
+                    : nothing}
                  ${chip.content}
                </ha-input-chip>
              `
@@ -9,9 +9,11 @@ import { css, html, LitElement } from "lit";
 import { customElement, state } from "lit/decorators";
 import { ifDefined } from "lit/directives/if-defined";
 import { repeat } from "lit/directives/repeat";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-control-switch";
+import type { HaControlSwitch } from "../../../../src/components/ha-control-switch";
+import type { HASSDomTargetEvent } from "../../../../src/common/dom/fire_event";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const switches: {
  id: string;
@@ -45,106 +47,72 @@ const switches: {
 export class DemoHaControlSwitch extends LitElement {
  @state() private checked = false;

-  handleValueChanged(e: any) {
-    this.checked = e.target.checked as boolean;
+  handleValueChanged(e: HASSDomTargetEvent<HaControlSwitch>) {
+    this.checked = e.target.checked;
  }

  protected render(): TemplateResult {
    return html`
-      <div class="themes">
-        ${["light", "dark"].map(
-          (mode) => html`
-            <div class=${mode}>
-              <ha-card header="ha-control-switch ${mode}">
-                ${repeat(switches, (sw) => {
-                  const { id, label, ...config } = sw;
-                  return html`
-                    <div class="card-content">
-                      <label id="${mode}-${id}">${label}</label>
-                      <pre>Config: ${JSON.stringify(config)}</pre>
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
+              ${repeat(switches, (sw) => {
+                const { id, label, ...config } = sw;
+                return html`
+                  <div class="card-content">
+                    <label id="${slot}-${id}">${label}</label>
+                    <pre>Config: ${JSON.stringify(config)}</pre>
+                    <ha-control-switch
+                      .checked=${this.checked}
+                      class=${ifDefined(config.class)}
+                      @change=${this.handleValueChanged}
+                      .pathOn=${mdiLightbulb}
+                      .pathOff=${mdiLightbulbOff}
+                      .label=${label}
+                      ?disabled=${config.disabled}
+                      ?reversed=${config.reversed}
+                    >
+                    </ha-control-switch>
+                  </div>
+                `;
+              })}
+              <div class="card-content">
+                <p class="title"><b>Vertical</b></p>
+                <div class="vertical-switches">
+                  ${repeat(switches, (sw) => {
+                    const { label, ...config } = sw;
+                    return html`
                      <ha-control-switch
                        .checked=${this.checked}
+                        vertical
                        class=${ifDefined(config.class)}
                        @change=${this.handleValueChanged}
-                        .pathOn=${mdiLightbulb}
-                        .pathOff=${mdiLightbulbOff}
                        .label=${label}
+                        .pathOn=${mdiGarageOpen}
+                        .pathOff=${mdiGarage}
                        ?disabled=${config.disabled}
                        ?reversed=${config.reversed}
                      >
                      </ha-control-switch>
-                    </div>
-                  `;
-                })}
-                <div class="card-content">
-                  <p class="title"><b>Vertical</b></p>
-                  <div class="vertical-switches">
-                    ${repeat(switches, (sw) => {
-                      const { label, ...config } = sw;
-                      return html`
-                        <ha-control-switch
-                          .checked=${this.checked}
-                          vertical
-                          class=${ifDefined(config.class)}
-                          @change=${this.handleValueChanged}
-                          .label=${label}
-                          .pathOn=${mdiGarageOpen}
-                          .pathOff=${mdiGarage}
-                          ?disabled=${config.disabled}
-                          ?reversed=${config.reversed}
-                        >
-                        </ha-control-switch>
-                      `;
-                    })}
-                  </div>
+                    `;
+                  })}
                </div>
-              </ha-card>
-            </div>
+              </div>
+            </ha-card>
          `
        )}
-      </div>
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
      display: block;
    }
-    .themes {
-      display: flex;
-      flex-direction: row;
-      justify-content: center;
-      flex-wrap: wrap;
-      gap: 16px;
-      padding: 16px;
-    }
-    .dark,
-    .light {
-      display: block;
-      background-color: var(--primary-background-color);
-      padding: 16px;
-      border-radius: var(--ha-border-radius-md);
-    }
    ha-card {
-      max-width: 600px;
-      margin: 0 auto;
+      margin: 0;
+      width: 100%;
    }
    pre {
      margin-top: 0;
@@ -8,25 +8,25 @@ import {
  mdiContentPaste,
  mdiDelete,
 } from "@mdi/js";
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-button";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-dropdown";
 import "../../../../src/components/ha-dropdown-item";
 import "../../../../src/components/ha-icon-button";
 import "../../../../src/components/ha-svg-icon";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

@customElement("demo-components-ha-dropdown")
 export class DemoHaDropdown extends LitElement {
  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-button in ${mode}">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                <ha-dropdown>
                  <ha-button slot="trigger" with-caret>Dropdown</ha-button>
@@ -74,45 +74,22 @@ export class DemoHaDropdown extends LitElement {
                </ha-dropdown>
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    .button {
      padding: unset;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -12,7 +12,7 @@ const SMALL_TEXT = "Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
 export class DemoHaFaded extends LitElement {
  protected render(): TemplateResult {
    return html`
-      <ha-card header="ha-faded demo">
+      <ha-card>
        <div class="card-content">
          <h3>Long text directly as slotted content</h3>
          <ha-faded>${LONG_TEXT}</ha-faded>
@@ -1,9 +1,8 @@
 import { ContextProvider } from "@lit/context";
 import { mdiMagnify } from "@mdi/js";
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-svg-icon";
 import "../../../../src/components/input/ha-input";
@@ -11,6 +10,15 @@ import "../../../../src/components/input/ha-input-copy";
 import "../../../../src/components/input/ha-input-multi";
 import "../../../../src/components/input/ha-input-search";
 import { internationalizationContext } from "../../../../src/data/context";
+import {
+  DateFormat,
+  FirstWeekday,
+  NumberFormat,
+  TimeFormat,
+  TimeZone,
+} from "../../../../src/data/translation";
+import type { HomeAssistantInternationalization } from "../../../../src/types";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const LOCALIZE_KEYS: Record<string, string> = {
  "ui.common.copy": "Copy",
@@ -22,6 +30,25 @@ const LOCALIZE_KEYS: Record<string, string> = {
  "ui.common.copied_clipboard": "Copied to clipboard",
 };

+const localize = (key: string) => LOCALIZE_KEYS[key] ?? key;
+
+const DEMO_I18N: HomeAssistantInternationalization = {
+  localize,
+  language: "en",
+  selectedLanguage: null,
+  locale: {
+    language: "en",
+    number_format: NumberFormat.language,
+    time_format: TimeFormat.language,
+    date_format: DateFormat.language,
+    first_weekday: FirstWeekday.language,
+    time_zone: TimeZone.local,
+  },
+  translationMetadata: { fragments: [], translations: {} },
+  loadBackendTranslation: async () => localize,
+  loadFragmentTranslation: async () => localize,
+};
+
@customElement("demo-components-ha-input")
 export class DemoHaInput extends LitElement {
  constructor() {
@@ -29,185 +56,171 @@ export class DemoHaInput extends LitElement {
    // Provides internationalizationContext for ha-input-copy, ha-input-multi and ha-input-search
    new ContextProvider(this, {
      context: internationalizationContext,
-      initialValue: {
-        localize: ((key: string) => LOCALIZE_KEYS[key] ?? key) as any,
-        language: "en",
-        selectedLanguage: null,
-        locale: {} as any,
-        translationMetadata: {} as any,
-        loadBackendTranslation: (async () => (key: string) => key) as any,
-        loadFragmentTranslation: (async () => (key: string) => key) as any,
-      },
+      initialValue: DEMO_I18N,
    });
  }

  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-input in ${mode}">
-              <div class="card-content">
-                <h3>Basic</h3>
-                <div class="row">
-                  <ha-input label="Default"></ha-input>
-                  <ha-input label="With value" value="Hello"></ha-input>
-                  <ha-input
-                    label="With placeholder"
-                    placeholder="Type here..."
-                  ></ha-input>
-                </div>
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <div slot=${slot} class="panel-content">
+              <ha-card>
+                <div class="card-content">
+                  <h3>Basic</h3>
+                  <div class="row">
+                    <ha-input label="Default"></ha-input>
+                    <ha-input label="With value" value="Hello"></ha-input>
+                    <ha-input
+                      label="With placeholder"
+                      placeholder="Type here..."
+                    ></ha-input>
+                  </div>

-                <h3>Input types</h3>
-                <div class="row">
-                  <ha-input label="Text" type="text" value="Text"></ha-input>
-                  <ha-input label="Number" type="number" value="42"></ha-input>
-                  <ha-input
-                    label="Email"
-                    type="email"
-                    placeholder="you@example.com"
-                  ></ha-input>
-                </div>
-                <div class="row">
-                  <ha-input
-                    label="Password"
-                    type="password"
-                    value="secret"
-                    password-toggle
-                  ></ha-input>
-                  <ha-input label="URL" type="url" placeholder="https://...">
-                  </ha-input>
-                  <ha-input label="Date" type="date"></ha-input>
-                </div>
+                  <h3>Input types</h3>
+                  <div class="row">
+                    <ha-input label="Text" type="text" value="Text"></ha-input>
+                    <ha-input
+                      label="Number"
+                      type="number"
+                      value="42"
+                    ></ha-input>
+                    <ha-input
+                      label="Email"
+                      type="email"
+                      placeholder="you@example.com"
+                    ></ha-input>
+                  </div>
+                  <div class="row">
+                    <ha-input
+                      label="Password"
+                      type="password"
+                      value="secret"
+                      password-toggle
+                    ></ha-input>
+                    <ha-input label="URL" type="url" placeholder="https://...">
+                    </ha-input>
+                    <ha-input label="Date" type="date"></ha-input>
+                  </div>

-                <h3>States</h3>
-                <div class="row">
-                  <ha-input
-                    label="Disabled"
-                    disabled
-                    value="Disabled"
-                  ></ha-input>
-                  <ha-input
-                    label="Readonly"
-                    readonly
-                    value="Readonly"
-                  ></ha-input>
-                  <ha-input label="Required" required></ha-input>
-                </div>
-                <div class="row">
-                  <ha-input
-                    label="Invalid"
-                    invalid
-                    validation-message="This field is required"
-                    value=""
-                  ></ha-input>
-                  <ha-input label="With hint" hint="This is a hint"></ha-input>
-                  <ha-input
-                    label="With clear"
-                    with-clear
-                    value="Clear me"
-                  ></ha-input>
-                </div>
+                  <h3>States</h3>
+                  <div class="row">
+                    <ha-input
+                      label="Disabled"
+                      disabled
+                      value="Disabled"
+                    ></ha-input>
+                    <ha-input
+                      label="Readonly"
+                      readonly
+                      value="Readonly"
+                    ></ha-input>
+                    <ha-input label="Required" required></ha-input>
+                  </div>
+                  <div class="row">
+                    <ha-input
+                      label="Invalid"
+                      invalid
+                      validation-message="This field is required"
+                      value=""
+                    ></ha-input>
+                    <ha-input
+                      label="With hint"
+                      hint="This is a hint"
+                    ></ha-input>
+                    <ha-input
+                      label="With clear"
+                      with-clear
+                      value="Clear me"
+                    ></ha-input>
+                  </div>

-                <h3>With slots</h3>
-                <div class="row">
-                  <ha-input label="With prefix">
-                    <span slot="start">$</span>
-                  </ha-input>
-                  <ha-input label="With suffix">
-                    <span slot="end">kg</span>
-                  </ha-input>
-                  <ha-input label="With icon">
-                    <ha-svg-icon .path=${mdiMagnify} slot="start"></ha-svg-icon>
-                  </ha-input>
+                  <h3>With slots</h3>
+                  <div class="row">
+                    <ha-input label="With prefix">
+                      <span slot="start">$</span>
+                    </ha-input>
+                    <ha-input label="With suffix">
+                      <span slot="end">kg</span>
+                    </ha-input>
+                    <ha-input label="With icon">
+                      <ha-svg-icon
+                        .path=${mdiMagnify}
+                        slot="start"
+                      ></ha-svg-icon>
+                    </ha-input>
+                  </div>
+
+                  <h3>Appearance: outlined</h3>
+                  <div class="row">
+                    <ha-input
+                      appearance="outlined"
+                      label="Outlined"
+                      value="Hello"
+                    ></ha-input>
+                    <ha-input
+                      appearance="outlined"
+                      label="Outlined disabled"
+                      disabled
+                      value="Disabled"
+                    ></ha-input>
+                    <ha-input
+                      appearance="outlined"
+                      label="Outlined invalid"
+                      invalid
+                      validation-message="Required"
+                    ></ha-input>
+                  </div>
+                  <div class="row">
+                    <ha-input
+                      appearance="outlined"
+                      placeholder="Placeholder only"
+                    ></ha-input>
+                  </div>
                </div>
+              </ha-card>

-                <h3>Appearance: outlined</h3>
-                <div class="row">
-                  <ha-input
-                    appearance="outlined"
-                    label="Outlined"
-                    value="Hello"
-                  ></ha-input>
-                  <ha-input
-                    appearance="outlined"
-                    label="Outlined disabled"
-                    disabled
-                    value="Disabled"
-                  ></ha-input>
-                  <ha-input
-                    appearance="outlined"
-                    label="Outlined invalid"
-                    invalid
-                    validation-message="Required"
-                  ></ha-input>
+              <ha-card header="Derivatives">
+                <div class="card-content">
+                  <h3>ha-input-search</h3>
+                  <ha-input-search label="Search label"></ha-input-search>
+                  <ha-input-search appearance="outlined"></ha-input-search>
+
+                  <h3>ha-input-copy</h3>
+                  <ha-input-copy
+                    value="my-api-token-123"
+                    masked-value="••••••••••••••••••"
+                    masked-toggle
+                  ></ha-input-copy>
+
+                  <h3>ha-input-multi</h3>
+                  <ha-input-multi
+                    label="URL"
+                    add-label="Add URL"
+                    .value=${["https://example.com"]}
+                  ></ha-input-multi>
                </div>
-                <div class="row">
-                  <ha-input
-                    appearance="outlined"
-                    placeholder="Placeholder only"
-                  ></ha-input>
-                </div>
-              </div>
-            </ha-card>
-
-            <ha-card header="Derivatives in ${mode}">
-              <div class="card-content">
-                <h3>ha-input-search</h3>
-                <ha-input-search label="Search label"></ha-input-search>
-                <ha-input-search appearance="outlined"></ha-input-search>
-
-                <h3>ha-input-copy</h3>
-                <ha-input-copy
-                  value="my-api-token-123"
-                  masked-value="••••••••••••••••••"
-                  masked-toggle
-                ></ha-input-copy>
-
-                <h3>ha-input-multi</h3>
-                <ha-input-multi
-                  label="URL"
-                  add-label="Add URL"
-                  .value=${["https://example.com"]}
-                ></ha-input-multi>
-              </div>
-            </ha-card>
-          </div>
-        `
-      )}
+              </ha-card>
+            </div>
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
+    }
+    .panel-content {
+      display: flex;
+      flex-direction: column;
+      gap: var(--ha-space-6);
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -224,10 +237,11 @@ export class DemoHaInput extends LitElement {
    }
    .row {
      display: flex;
+      flex-wrap: wrap;
      gap: var(--ha-space-4);
    }
    .row > * {
-      flex: 1;
+      flex: 1 1 180px;
    }
  `;
 }
@@ -1,20 +1,21 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
+import type { HASSDomCurrentTargetEvent } from "../../../../src/common/dom/fire_event";
 import "../../../../src/components/buttons/ha-progress-button";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-svg-icon";
 import { mdiHomeAssistant } from "../../../../src/resources/home-assistant-logo-svg";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

@customElement("demo-components-ha-progress-button")
 export class DemoHaProgressButton extends LitElement {
  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-progress-button in ${mode}">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                <ha-progress-button @click=${this._clickedSuccess}>
                  Success
@@ -59,32 +60,17 @@ export class DemoHaProgressButton extends LitElement {
                </ha-progress-button>
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
-  private async _clickedSuccess(ev: CustomEvent): Promise<void> {
+  private _clickedSuccess(
+    ev: HASSDomCurrentTargetEvent<HTMLElementTagNameMap["ha-progress-button"]>
+  ) {
    console.log("Clicked success");
-    const button = ev.currentTarget as any;
+    const button = ev.currentTarget;
    button.progress = true;

    setTimeout(() => {
@@ -93,8 +79,10 @@ export class DemoHaProgressButton extends LitElement {
    }, 1000);
  }

-  private async _clickedFail(ev: CustomEvent): Promise<void> {
-    const button = ev.currentTarget as any;
+  private _clickedFail(
+    ev: HASSDomCurrentTargetEvent<HTMLElementTagNameMap["ha-progress-button"]>
+  ) {
+    const button = ev.currentTarget;
    button.progress = true;

    setTimeout(() => {
@@ -105,20 +93,14 @@ export class DemoHaProgressButton extends LitElement {

  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    .button {
      padding: unset;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -1,12 +1,12 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement, property } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-bar";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-spinner";
 import "../../../../src/components/ha-slider";
 import type { HomeAssistant } from "../../../../src/types";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

@customElement("demo-components-ha-slider")
 export class DemoHaSlider extends LitElement {
@@ -14,10 +14,10 @@ export class DemoHaSlider extends LitElement {

  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-slider ${mode} demo">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                <span>Default (disabled)</span>
                <ha-slider
@@ -45,44 +45,19 @@ export class DemoHaSlider extends LitElement {
                ></ha-slider>
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
-      margin: 16px;
-      border-radius: var(--ha-border-radius-md);
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -1,11 +1,11 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement, property } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-bar";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-spinner";
 import type { HomeAssistant } from "../../../../src/types";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

@customElement("demo-components-ha-spinner")
 export class DemoHaSpinner extends LitElement {
@@ -13,10 +13,10 @@ export class DemoHaSpinner extends LitElement {

  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-badge ${mode} demo">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                <ha-spinner></ha-spinner>
                <ha-spinner size="tiny"></ha-spinner>
@@ -27,44 +27,19 @@ export class DemoHaSpinner extends LitElement {
                <ha-spinner .ariaLabel=${"Doing something..."}></ha-spinner>
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
-      margin: 16px;
-      border-radius: var(--ha-border-radius-md);
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -1,10 +1,10 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement, property } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-switch";
 import type { HomeAssistant } from "../../../../src/types";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

@customElement("demo-components-ha-switch")
 export class DemoHaSwitch extends LitElement {
@@ -12,10 +12,10 @@ export class DemoHaSwitch extends LitElement {

  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-switch ${mode}">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                <div class="row">
                  <span>Unchecked</span>
@@ -35,44 +35,19 @@ export class DemoHaSwitch extends LitElement {
                </div>
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
-      margin: 16px;
-      border-radius: var(--ha-border-radius-md);
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -1,18 +1,23 @@
-import type { TemplateResult, PropertyValues } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-textarea";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";
+
+const LONG_VALUE = Array.from(
+  { length: 30 },
+  (_, i) => `Line ${i + 1}: this content overflows the max-height and scrolls.`
+).join("\n");

@customElement("demo-components-ha-textarea")
 export class DemoHaTextarea extends LitElement {
  protected render(): TemplateResult {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <ha-card header="ha-textarea in ${mode}">
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
              <div class="card-content">
                <h3>Basic</h3>
                <div class="row">
@@ -38,6 +43,11 @@ export class DemoHaTextarea extends LitElement {
                    resize="auto"
                    value="This textarea will grow as you type more content into it. Try adding more lines to see the effect."
                  ></ha-textarea>
+                  <ha-textarea
+                    label="Autogrow capped (scrolls past max-height)"
+                    resize="auto"
+                    .value=${LONG_VALUE}
+                  ></ha-textarea>
                </div>

                <h3>States</h3>
@@ -84,42 +94,19 @@ export class DemoHaTextarea extends LitElement {
                </div>
              </div>
            </ha-card>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      justify-content: center;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
    .card-content {
      display: flex;
@@ -1,12 +1,19 @@
 import { provide } from "@lit/context";
-import type { PropertyValues, TemplateResult } from "lit";
+import type { TemplateResult } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement, state } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-tip";
 import { internationalizationContext } from "../../../../src/data/context";
+import {
+  DateFormat,
+  FirstWeekday,
+  NumberFormat,
+  TimeFormat,
+  TimeZone,
+} from "../../../../src/data/translation";
 import type { HomeAssistantInternationalization } from "../../../../src/types";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const tips: (string | TemplateResult)[] = [
  "Test tip",
@@ -14,68 +21,57 @@ const tips: (string | TemplateResult)[] = [
  html`<i>Tip</i> <b>with</b> <sub>HTML</sub>`,
 ];

+const localize = (key: string) => key;
+
+const DEMO_I18N: HomeAssistantInternationalization = {
+  localize,
+  language: "en",
+  selectedLanguage: null,
+  locale: {
+    language: "en",
+    number_format: NumberFormat.language,
+    time_format: TimeFormat.language,
+    date_format: DateFormat.language,
+    first_weekday: FirstWeekday.language,
+    time_zone: TimeZone.local,
+  },
+  translationMetadata: { fragments: [], translations: {} },
+  loadBackendTranslation: async () => localize,
+  loadFragmentTranslation: async () => localize,
+};
+
@customElement("demo-components-ha-tip")
 export class DemoHaTip extends LitElement {
  @provide({ context: internationalizationContext })
  @state()
-  protected _i18n: HomeAssistantInternationalization = {
-    localize: ((key: string) => key) as any,
-    language: "en",
-    selectedLanguage: null,
-    locale: {} as any,
-    translationMetadata: {} as any,
-    loadBackendTranslation: (async () => (key: string) => key) as any,
-    loadFragmentTranslation: (async () => (key: string) => key) as any,
-  };
+  protected _i18n = DEMO_I18N;

  protected render(): TemplateResult {
-    return html` ${["light", "dark"].map(
-      (mode) => html`
-        <div class=${mode}>
-          <ha-card header="ha-tip ${mode} demo">
-            <div class="card-content">
-              ${tips.map((tip) => html`<ha-tip>${tip}</ha-tip>`)}
-            </div>
-          </ha-card>
-        </div>
-      `
-    )}`;
-  }
-
-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
+    return html`
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <ha-card slot=${slot}>
+              <div class="card-content">
+                ${tips.map((tip) => html`<ha-tip>${tip}</ha-tip>`)}
+              </div>
+            </ha-card>
+          `
+        )}
+      </demo-theme-comparison>
+    `;
  }

  static styles = css`
    :host {
-      display: flex;
-      flex-direction: row;
-      justify-content: space-between;
-    }
-    .dark,
-    .light {
      display: block;
-      background-color: var(--primary-background-color);
-      padding: 0 50px;
    }
    ha-tip {
      margin-bottom: 14px;
    }
    ha-card {
-      margin: 24px auto;
+      margin: 0;
+      width: 100%;
    }
  `;
 }
@@ -4,21 +4,30 @@ title: Home

 # Welcome to Home Assistant Design

-This portal aims to aid designers and developers on improving the Home Assistant interface. It consists of working code, resources and guidelines.
+This is the design gallery for the Home Assistant frontend: a living reference of working components, dashboard cards, and brand and copy guidance. Every page runs outside a Home Assistant instance, so you can explore the interface, try components in isolation, and review changes against a consistent baseline.

-## Home Assistant interface
+## Browse the gallery

-The Home Assistant frontend allows users to browse and control the state of their home, manage their automations and configure integrations. The frontend is designed as a mobile-first experience. It is a progressive web application and offers an app-like experience to our users. The Home Assistant frontend needs to be fast. But it also needs to work on a wide range of old devices.
+- [Brand](#brand/logo): the logo, personality, and the story behind the Open Home.
+- [Components](#components/ha-button): the `ha-*` component library with live demos and API notes.
+- [Dashboards](#lovelace/introduction): Lovelace cards rendered from real card configuration.
+- [More Info dialogs](#more-info/light): the more-info experience for each entity type.
+- [Automation](#automation/editor-trigger): trigger, condition, and action editors, plus trace views.
+- [Users](#user-test/user-types): the audiences we design for.
+- [Date and time](#date-time/date): date and time formatting examples.
+- [Miscellaneous](#misc/entity-state): smaller utilities and patterns, plus how to edit this gallery.

-### Material Design
+## Testing and playground

-The Home Assistant interface is based on Material Design. It's a design system created by Google to quickly build high-quality digital experiences. Components and guidelines that are custom made for Home Assistant are documented on this portal. For all other components check <a href="https://material.io" rel="noopener noreferrer" target="_blank">material.io</a>.
+Every page runs against fake state, so you can interact with components safely and reproducibly. Treat the demo pages as a playground: change a value, resize the window, or switch the layout to right-to-left to check spacing and direction. Use the gallery to reproduce a UI state in isolation before debugging it in a full Home Assistant setup.
+
+Open **Settings** from the gear icon in the sidebar to switch between light and dark themes or preview the interface in right-to-left.

 ## Designers

-We want to make it as easy for designers to contribute as it is for developers. There’s a lot a designer can contribute to:
+We want to make it as easy for designers to contribute as it is for developers. There's a lot a designer can contribute to:

- Meet us at <a href="https://www.home-assistant.io/join-chat-design" rel="noopener noreferrer" target="_blank">Discord #designers channel</a>. If you can't see the channel, make sure you set the correct role in Channels & Roles.
+- Meet us in the <a href="https://www.home-assistant.io/join-chat-design" rel="noopener noreferrer" target="_blank">Discord #designers channel</a>. If you can't see the channel, make sure you set the correct role in Channels & Roles.
 - Start designing with our <a href="https://www.figma.com/design/2WGI8IDGyxINjSV6NRvPur/Home-Assistant-Design-Kit" rel="noopener noreferrer" target="_blank">Figma DesignKit</a>.
 - Find the latest UX <a href="https://github.com/home-assistant/frontend/discussions?discussions_q=label%3Aux" rel="noopener noreferrer" target="_blank">discussions</a> and <a href="https://github.com/home-assistant/frontend/labels/ux" rel="noopener noreferrer" target="_blank">issues</a> on GitHub. Everyone can start a new issue or discussion!

@@ -1,7 +1,6 @@
-import type { PropertyValues } from "lit";
 import { css, html, LitElement } from "lit";
 import { customElement } from "lit/decorators";
-import { applyThemesOnElement } from "../../../../src/common/dom/apply_themes_on_element";
+import { THEME_COMPARISON_PANELS } from "../../components/demo-theme-comparison";

 const SHADOWS = ["s", "m", "l"] as const;

@@ -9,67 +8,32 @@ const SHADOWS = ["s", "m", "l"] as const;
 export class DemoMiscBoxShadow extends LitElement {
  protected render() {
    return html`
-      ${["light", "dark"].map(
-        (mode) => html`
-          <div class=${mode}>
-            <h2>${mode}</h2>
-            <div class="grid">
-              ${SHADOWS.map(
-                (size) => html`
-                  <div
-                    class="box"
-                    style="box-shadow: var(--ha-box-shadow-${size})"
-                  >
-                    ${size}
-                  </div>
-                `
-              )}
+      <demo-theme-comparison>
+        ${THEME_COMPARISON_PANELS.map(
+          ({ slot }) => html`
+            <div slot=${slot} class="panel-content">
+              <div class="grid">
+                ${SHADOWS.map(
+                  (size) => html`
+                    <div
+                      class="box"
+                      style="box-shadow: var(--ha-box-shadow-${size})"
+                    >
+                      ${size}
+                    </div>
+                  `
+                )}
+              </div>
            </div>
-          </div>
-        `
-      )}
+          `
+        )}
+      </demo-theme-comparison>
    `;
  }

-  firstUpdated(changedProps: PropertyValues<this>) {
-    super.firstUpdated(changedProps);
-    applyThemesOnElement(
-      this.shadowRoot!.querySelector(".dark"),
-      {
-        default_theme: "default",
-        default_dark_theme: "default",
-        themes: {},
-        darkMode: true,
-        theme: "default",
-      },
-      undefined,
-      undefined,
-      true
-    );
-  }
-
  static styles = css`
    :host {
-      display: flex;
-      flex-direction: row;
-      gap: 48px;
-      padding: 48px;
-    }
-
-    .light,
-    .dark {
-      flex: 1;
-      background-color: var(--primary-background-color);
-      border-radius: 16px;
-      padding: 32px;
-    }
-
-    h2 {
-      margin: 0 0 24px;
-      font-size: 18px;
-      font-weight: 500;
-      color: var(--primary-text-color);
-      text-transform: capitalize;
+      display: block;
    }

    .grid {
@@ -10,7 +10,7 @@ All pages are stored in [the pages folder][pages-folder] on GitHub. Pages are gr

 ## Development

-You can develop design.home-assistant.io locally by checking out [the Home Assistant frontend repository](https://github.com/home-assistant/frontend). The command to run the gallery is `gallery/script/develop_gallery`. It will automatically open a browser window and load the development version of the website.
+You can develop design.home-assistant.io locally by checking out [the Home Assistant frontend repository](https://github.com/home-assistant/frontend). The command to run the gallery is `gallery/script/develop_gallery`. After the first build finishes, the command prints the local URL for the development version of the website.

 ## Creating a page

@@ -372,7 +372,6 @@ export class DemoEntityState extends LitElement {
              hass.localize,
              entry.stateObj,
              hass.locale,
-              [], // numericDeviceClasses
              hass.config,
              hass.entities
            )}`,
@@ -21,7 +21,17 @@
    "prepack": "pinst --disable",
    "postpack": "pinst --enable",
    "test": "vitest run --config test/vitest.config.ts",
-    "test:coverage": "vitest run --config test/vitest.config.ts --coverage"
+    "test:bench": "vitest bench --run --config test/vitest.bench.config.ts",
+    "test:coverage": "vitest run --config test/vitest.config.ts --coverage",
+    "test:e2e": "node test/e2e/run-suites.mjs demo app gallery",
+    "test:e2e:browserstack": "node test/e2e/run-suites.mjs demo:browserstack app:browserstack gallery:browserstack",
+    "test:e2e:show-report": "yarn playwright show-report test/e2e/reports/combined",
+    "test:e2e:demo": "playwright test --config test/e2e/playwright.demo.config.ts",
+    "test:e2e:demo:browserstack": "browserstack-node-sdk playwright test --config test/e2e/playwright.demo.config.ts",
+    "test:e2e:app": "playwright test --config test/e2e/playwright.app.config.ts",
+    "test:e2e:app:browserstack": "browserstack-node-sdk playwright test --config test/e2e/playwright.app.config.ts",
+    "test:e2e:gallery": "playwright test --config test/e2e/playwright.gallery.config.ts",
+    "test:e2e:gallery:browserstack": "browserstack-node-sdk playwright test --config test/e2e/playwright.gallery.config.ts"
  },
  "author": "Paulus Schoutsen <Paulus@PaulusSchoutsen.nl> (http://paulusschoutsen.nl)",
  "license": "Apache-2.0",
@@ -29,26 +39,26 @@
  "dependencies": {
    "@babel/runtime": "7.29.7",
    "@braintree/sanitize-url": "7.1.2",
-    "@codemirror/autocomplete": "6.20.2",
+    "@codemirror/autocomplete": "6.20.3",
    "@codemirror/commands": "6.10.3",
    "@codemirror/lang-jinja": "6.0.1",
    "@codemirror/lang-yaml": "6.1.3",
    "@codemirror/language": "6.12.3",
-    "@codemirror/lint": "6.9.6",
+    "@codemirror/lint": "6.9.7",
    "@codemirror/search": "6.7.0",
    "@codemirror/state": "6.6.0",
-    "@codemirror/view": "6.43.0",
+    "@codemirror/view": "6.43.1",
    "@date-fns/tz": "1.5.0",
    "@egjs/hammerjs": "2.0.17",
-    "@formatjs/intl-datetimeformat": "7.4.7",
-    "@formatjs/intl-displaynames": "7.3.9",
-    "@formatjs/intl-durationformat": "0.10.13",
-    "@formatjs/intl-getcanonicallocales": "3.2.9",
-    "@formatjs/intl-listformat": "8.3.9",
-    "@formatjs/intl-locale": "5.3.8",
-    "@formatjs/intl-numberformat": "9.3.10",
-    "@formatjs/intl-pluralrules": "6.3.9",
-    "@formatjs/intl-relativetimeformat": "12.3.9",
+    "@formatjs/intl-datetimeformat": "7.4.9",
+    "@formatjs/intl-displaynames": "7.3.10",
+    "@formatjs/intl-durationformat": "0.10.14",
+    "@formatjs/intl-getcanonicallocales": "3.2.10",
+    "@formatjs/intl-listformat": "8.3.10",
+    "@formatjs/intl-locale": "5.3.9",
+    "@formatjs/intl-numberformat": "9.3.11",
+    "@formatjs/intl-pluralrules": "6.3.10",
+    "@formatjs/intl-relativetimeformat": "12.3.10",
    "@fullcalendar/core": "6.1.20",
    "@fullcalendar/daygrid": "6.1.20",
    "@fullcalendar/interaction": "6.1.20",
@@ -70,8 +80,8 @@
    "@replit/codemirror-indentation-markers": "6.5.3",
    "@swc/helpers": "0.5.23",
    "@thomasloven/round-slider": "0.6.0",
-    "@tsparticles/engine": "4.1.2",
-    "@tsparticles/preset-links": "4.1.2",
+    "@tsparticles/engine": "4.1.3",
+    "@tsparticles/preset-links": "4.1.3",
    "@vibrant/color": "4.0.4",
    "@webcomponents/scoped-custom-element-registry": "0.0.10",
    "@webcomponents/webcomponentsjs": "2.8.0",
@@ -88,13 +98,13 @@
    "dialog-polyfill": "0.5.6",
    "echarts": "6.1.0",
    "element-internals-polyfill": "3.0.2",
-    "fuse.js": "7.4.1",
+    "fuse.js": "7.4.2",
    "google-timezones-json": "1.2.0",
    "gulp-zopfli-green": "7.0.0",
    "hls.js": "1.6.16",
    "home-assistant-js-websocket": "9.6.0",
    "idb-keyval": "6.2.5",
-    "intl-messageformat": "11.2.7",
+    "intl-messageformat": "11.2.8",
    "js-yaml": "4.2.0",
    "leaflet": "1.9.4",
    "leaflet-draw": "patch:leaflet-draw@npm%3A1.0.4#./.yarn/patches/leaflet-draw-npm-1.0.4-0ca0ebcf65.patch",
@@ -102,7 +112,7 @@
    "lit": "3.3.3",
    "lit-html": "3.3.3",
    "luxon": "3.7.2",
-    "marked": "18.0.4",
+    "marked": "18.0.5",
    "memoize-one": "6.0.0",
    "node-vibrant": "4.0.4",
    "object-hash": "3.0.0",
@@ -131,14 +141,16 @@
    "@babel/preset-env": "7.29.7",
    "@bundle-stats/plugin-webpack-filter": "4.22.2",
    "@eslint/js": "10.0.1",
-    "@html-eslint/eslint-plugin": "0.61.0",
+    "@html-eslint/eslint-plugin": "0.62.0",
    "@lokalise/node-api": "16.0.0",
    "@octokit/auth-oauth-device": "8.0.3",
    "@octokit/plugin-retry": "8.1.0",
    "@octokit/rest": "22.0.1",
-    "@rsdoctor/rspack-plugin": "1.5.12",
-    "@rspack/core": "2.0.6",
+    "@playwright/test": "1.60.0",
+    "@rsdoctor/rspack-plugin": "1.5.13",
+    "@rspack/core": "2.0.8",
    "@rspack/dev-server": "2.0.3",
+    "@types/babel__plugin-transform-runtime": "7.9.5",
    "@types/chromecast-caf-receiver": "6.0.26",
    "@types/chromecast-caf-sender": "1.0.11",
    "@types/color-name": "2.0.0",
@@ -157,8 +169,9 @@
    "babel-loader": "10.1.1",
    "babel-plugin-template-html-minifier": "4.1.0",
    "browserslist-useragent-regexp": "4.1.4",
+    "browserstack-node-sdk": "1.53.2",
    "del": "8.0.1",
-    "eslint": "10.4.1",
+    "eslint": "10.5.0",
    "eslint-config-prettier": "10.1.8",
    "eslint-import-resolver-webpack": "0.13.11",
    "eslint-plugin-import-x": "4.16.2",
@@ -186,15 +199,15 @@
    "lodash.template": "4.18.1",
    "map-stream": "0.0.7",
    "pinst": "3.0.0",
-    "prettier": "3.8.3",
-    "rspack-manifest-plugin": "5.2.1",
+    "prettier": "3.8.4",
+    "rspack-manifest-plugin": "5.2.2",
    "serve": "14.2.6",
    "sinon": "22.0.0",
    "tar": "7.5.16",
    "terser-webpack-plugin": "5.6.1",
    "ts-lit-plugin": "2.0.2",
    "typescript": "6.0.3",
-    "typescript-eslint": "8.60.1",
+    "typescript-eslint": "8.61.0",
    "vite-tsconfig-paths": "6.1.1",
    "vitest": "4.1.8",
    "webpack-stats-plugin": "1.1.3",
@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+# Safe bash settings
+# -e            Exit on command fail
+# -u            Exit on unset variable
+# -o pipefail   Exit if piped command has error code
+set -eu -o pipefail
+
+cd "$(dirname "$0")/.."
+
+./node_modules/.bin/gulp gen-numeric-device-classes
@@ -4,8 +4,7 @@ import { ensureArray } from "../array/ensure-array";
 import { isComponentLoaded } from "./is_component_loaded";

 export const canShowPage = (hass: HomeAssistant, page: PageNavigation) =>
-  (isCore(page) || isLoadedIntegration(hass, page)) &&
-  isNotLoadedIntegration(hass, page);
+  isCore(page) || isLoadedIntegration(hass, page);

 export const isLoadedIntegration = (
  hass: HomeAssistant,
@@ -16,13 +15,4 @@ export const isLoadedIntegration = (
    isComponentLoaded(hass.config, integration)
  );

-export const isNotLoadedIntegration = (
-  hass: HomeAssistant,
-  page: PageNavigation
-) =>
-  !page.not_component ||
-  !ensureArray(page.not_component).some((integration) =>
-    isComponentLoaded(hass.config, integration)
-  );
-
 export const isCore = (page: PageNavigation) => page.core;
@@ -1,7 +1,7 @@
 // Load a resource and get a promise when loading done.
 // From: https://davidwalsh.name/javascript-loader

-const _load = (tag: "link" | "script" | "img", url: string, type?: "module") =>
+const _load = (tag: "link" | "script", url: string, type?: "module") =>
  // This promise will be used by Promise.all to determine success or failure
  new Promise((resolve, reject) => {
    const element = document.createElement(tag);
@@ -33,5 +33,4 @@ const _load = (tag: "link" | "script" | "img", url: string, type?: "module") =>
  });
 export const loadCSS = (url: string) => _load("link", url);
 export const loadJS = (url: string) => _load("script", url);
-export const loadImg = (url: string) => _load("img", url);
 export const loadModule = (url: string) => _load("script", url, "module");
@@ -1,41 +0,0 @@
-/**
- * Scroll to a specific y coordinate.
- *
- * Copied from paper-scroll-header-panel.
- *
- * @method scroll
- * @param {number} top The coordinate to scroll to, along the y-axis.
- * @param {boolean} smooth true if the scroll position should be smoothly adjusted.
- */
-export default function scrollToTarget(element, target) {
-  // the scroll event will trigger _updateScrollState directly,
-  // However, _updateScrollState relies on the previous `scrollTop` to update the states.
-  // Calling _updateScrollState will ensure that the states are synced correctly.
-  const top = 0;
-  const scroller = target;
-  const easingFn = function easeOutQuad(t, b, c, d) {
-    t /= d;
-    return -c * t * (t - 2) + b;
-  };
-  const animationId = Math.random();
-  const duration = 200;
-  const startTime = Date.now();
-  const currentScrollTop = scroller.scrollTop;
-  const deltaScrollTop = top - currentScrollTop;
-  element._currentAnimationId = animationId;
-  (function updateFrame() {
-    const now = Date.now();
-    const elapsedTime = now - startTime;
-    if (elapsedTime > duration) {
-      scroller.scrollTop = top;
-    } else if (element._currentAnimationId === animationId) {
-      scroller.scrollTop = easingFn(
-        elapsedTime,
-        currentScrollTop,
-        deltaScrollTop,
-        duration
-      );
-      requestAnimationFrame(updateFrame.bind(element));
-    }
-  }).call(element);
-}
@@ -3,8 +3,6 @@ import type { Map, TileLayer } from "leaflet";
 // Sets up a Leaflet map on the provided DOM element
 // eslint-disable-next-line @typescript-eslint/consistent-type-imports
 export type LeafletModuleType = typeof import("leaflet");
-// eslint-disable-next-line @typescript-eslint/consistent-type-imports
-export type LeafletDrawModuleType = typeof import("leaflet-draw");

 export const setupLeafletMap = async (
  mapElement: HTMLElement,
@@ -45,17 +43,6 @@ export const setupLeafletMap = async (
  return [map, Leaflet, tileLayer];
 };

-export const replaceTileLayer = (
-  leaflet: LeafletModuleType,
-  map: Map,
-  tileLayer: TileLayer
-): TileLayer => {
-  map.removeLayer(tileLayer);
-  tileLayer = createTileLayer(leaflet);
-  tileLayer.addTo(map);
-  return tileLayer;
-};
-
 const createTileLayer = (leaflet: LeafletModuleType): TileLayer =>
  leaflet.tileLayer(
    `https://basemaps.cartocdn.com/rastertiles/voyager/{z}/{x}/{y}${
@@ -1,3 +0,0 @@
-/** An empty image which can be set as src of an img element. */
-export const emptyImageBase64 =
-  "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7";
@@ -17,13 +17,51 @@ import {
 import { blankBeforeUnit } from "../translations/blank_before_unit";
 import type { LocalizeFunc } from "../translations/localize";
 import { computeDomain } from "./compute_domain";
-import { SENSOR_TIMESTAMP_DEVICE_CLASSES } from "../../data/sensor";
+import {
+  isNumericSensorDeviceClass,
+  SENSOR_TIMESTAMP_DEVICE_CLASSES,
+} from "../../data/sensor";
+
+// Domains whose state is a timezone-agnostic date and/or time string.
+const DATE_TIME_DOMAINS = new Set(["date", "input_datetime", "time"]);
+
+// Domains whose state is a timestamp.
+const TIMESTAMP_DOMAINS = new Set([
+  "ai_task",
+  "button",
+  "conversation",
+  "event",
+  "image",
+  "infrared",
+  "input_button",
+  "notify",
+  "radio_frequency",
+  "scene",
+  "stt",
+  "tag",
+  "tts",
+  "wake_word",
+  "datetime",
+]);
+
+// Maps Intl.NumberFormat part types to ValuePart types for monetary states.
+const MONETARY_TYPE_MAP: Record<string, ValuePart["type"]> = {
+  integer: "value",
+  group: "value",
+  decimal: "value",
+  fraction: "value",
+  minusSign: "value",
+  plusSign: "value",
+  literal: "literal",
+  currency: "unit",
+};
+
+const NUMERICAL_DOMAINS = ["counter", "input_number", "number"];

 export const computeStateDisplay = (
  localize: LocalizeFunc,
  stateObj: HassEntity,
  locale: FrontendLocaleData,
-  sensorNumericDeviceClasses: string[],
  config: HassConfig,
  entities: HomeAssistant["entities"],
  state?: string
@@ -34,7 +72,6 @@ export const computeStateDisplay = (
  return computeStateDisplayFromEntityAttributes(
    localize,
    locale,
-    sensorNumericDeviceClasses,
    config,
    entity,
    stateObj.entity_id,
@@ -46,7 +83,6 @@ export const computeStateDisplay = (
 export const computeStateDisplayFromEntityAttributes = (
  localize: LocalizeFunc,
  locale: FrontendLocaleData,
-  sensorNumericDeviceClasses: string[],
  config: HassConfig,
  entity: EntityRegistryDisplayEntry | undefined,
  entityId: string,
@@ -56,7 +92,6 @@ export const computeStateDisplayFromEntityAttributes = (
  const parts = computeStateToPartsFromEntityAttributes(
    localize,
    locale,
-    sensorNumericDeviceClasses,
    config,
    entity,
    entityId,
@@ -69,7 +104,6 @@ export const computeStateDisplayFromEntityAttributes = (
 const computeStateToPartsFromEntityAttributes = (
  localize: LocalizeFunc,
  locale: FrontendLocaleData,
-  sensorNumericDeviceClasses: string[],
  config: HassConfig,
  entity: EntityRegistryDisplayEntry | undefined,
  entityId: string,
@@ -86,15 +120,15 @@ const computeStateToPartsFromEntityAttributes = (
  }

  const domain = computeDomain(entityId);
-  const is_number_domain =
-    domain === "counter" || domain === "number" || domain === "input_number";
-  // Entities with a `unit_of_measurement` or `state_class` are numeric values and should use `formatNumber`
+  const isNumberDomain = NUMERICAL_DOMAINS.includes(domain);
+  const isSensorDomain = domain === "sensor";
+
+  // Numeric values (by attributes, number domain,
+  // or numeric sensor device class) use formatNumber.
  if (
-    isNumericFromAttributes(
-      attributes,
-      domain === "sensor" ? sensorNumericDeviceClasses : []
-    ) ||
-    is_number_domain
+    isNumericFromAttributes(attributes) ||
+    isNumberDomain ||
+    (isSensorDomain && isNumericSensorDeviceClass(attributes.device_class))
  ) {
    // state is duration
    if (
@@ -138,21 +172,10 @@ const computeStateToPartsFromEntityAttributes = (
      }

      if (parts.length) {
-        const TYPE_MAP: Record<string, ValuePart["type"]> = {
-          integer: "value",
-          group: "value",
-          decimal: "value",
-          fraction: "value",
-          minusSign: "value",
-          plusSign: "value",
-          literal: "literal",
-          currency: "unit",
-        };
-
        const valueParts: ValuePart[] = [];

        for (const part of parts) {
-          const type = TYPE_MAP[part.type];
+          const type = MONETARY_TYPE_MAP[part.type];
          if (!type) continue;
          const last = valueParts[valueParts.length - 1];
          // Merge consecutive value parts (e.g. "-" + "12" + "." + "00" → "-12.00")
@@ -191,7 +214,7 @@ const computeStateToPartsFromEntityAttributes = (
    return [{ type: "value", value: value }];
  }

-  if (["date", "input_datetime", "time"].includes(domain)) {
+  if (DATE_TIME_DOMAINS.has(domain)) {
    // If trying to display an explicit state, need to parse the explicit state to `Date` then format.
    // Attributes aren't available, we have to use `state`.

@@ -250,23 +273,7 @@ const computeStateToPartsFromEntityAttributes = (

  // state is a timestamp
  if (
-    [
-      "ai_task",
-      "button",
-      "conversation",
-      "event",
-      "image",
-      "infrared",
-      "input_button",
-      "notify",
-      "radio_frequency",
-      "scene",
-      "stt",
-      "tag",
-      "tts",
-      "wake_word",
-      "datetime",
-    ].includes(domain) ||
+    TIMESTAMP_DOMAINS.has(domain) ||
    (domain === "sensor" &&
      SENSOR_TIMESTAMP_DEVICE_CLASSES.includes(attributes.device_class))
  ) {
@@ -307,7 +314,6 @@ export const computeStateToParts = (
  localize: LocalizeFunc,
  stateObj: HassEntity,
  locale: FrontendLocaleData,
-  sensorNumericDeviceClasses: string[],
  config: HassConfig,
  entities: HomeAssistant["entities"],
  state?: string
@@ -318,7 +324,6 @@ export const computeStateToParts = (
  return computeStateToPartsFromEntityAttributes(
    localize,
    locale,
-    sensorNumericDeviceClasses,
    config,
    entity,
    stateObj.entity_id,
@@ -4,9 +4,10 @@ import { updateIsInstalling } from "../../data/update";

 export const updateIcon = (stateObj: HassEntity, state?: string) => {
  const compareState = state ?? stateObj.state;
-  return compareState === "on"
-    ? updateIsInstalling(stateObj as UpdateEntity)
-      ? "mdi:package-down"
-      : "mdi:package-up"
-    : "mdi:package";
+  // An install can be in progress even when the state is "off", e.g. when
+  // downgrading firmware. Show the installing icon regardless of state.
+  if (updateIsInstalling(stateObj as UpdateEntity)) {
+    return "mdi:package-down";
+  }
+  return compareState === "on" ? "mdi:package-up" : "mdi:package";
 };
@@ -14,12 +14,8 @@ export const isNumericState = (stateObj: HassEntity): boolean =>
  isNumericFromAttributes(stateObj.attributes);

 export const isNumericFromAttributes = (
-  attributes: HassEntityAttributeBase,
-  numericDeviceClasses?: string[]
-): boolean =>
-  !!attributes.unit_of_measurement ||
-  !!attributes.state_class ||
-  (numericDeviceClasses || []).includes(attributes.device_class || "");
+  attributes: HassEntityAttributeBase
+): boolean => !!attributes.unit_of_measurement || !!attributes.state_class;

 export const numberFormatToLocale = (
  localeOptions: FrontendLocaleData
@@ -40,6 +36,25 @@ export const numberFormatToLocale = (
  }
 };

+// Constructing an Intl.NumberFormat is comparatively expensive, and these
+// formatters are created on every numeric state render. The number of distinct
+// (locale, options) combinations is small and bounded in practice, so cache the
+// instances instead of rebuilding them on every call.
+const numberFormatCache = new Map<string, Intl.NumberFormat>();
+
+const getNumberFormatter = (
+  locale: string | string[] | undefined,
+  options: Intl.NumberFormatOptions
+): Intl.NumberFormat => {
+  const key = JSON.stringify([locale, options]);
+  let formatter = numberFormatCache.get(key);
+  if (!formatter) {
+    formatter = new Intl.NumberFormat(locale, options);
+    numberFormatCache.set(key, formatter);
+  }
+  return formatter;
+};
+
 /**
 * Formats a number based on the user's preference with thousands separator(s) and decimal character for better legibility.
 *
@@ -75,7 +90,7 @@ export const formatNumberToParts = (
    localeOptions?.number_format !== NumberFormat.none &&
    !Number.isNaN(Number(num))
  ) {
-    return new Intl.NumberFormat(
+    return getNumberFormatter(
      locale,
      getDefaultFormatOptions(num, options)
    ).formatToParts(Number(num));
@@ -87,7 +102,7 @@ export const formatNumberToParts = (
    localeOptions?.number_format === NumberFormat.none
  ) {
    // If NumberFormat is none, use en-US format without grouping.
-    return new Intl.NumberFormat(
+    return getNumberFormatter(
      "en-US",
      getDefaultFormatOptions(num, {
        ...options,
@@ -46,8 +46,7 @@ export const computeFormatFunctions = async (
  entities: HomeAssistant["entities"],
  devices: HomeAssistant["devices"],
  areas: HomeAssistant["areas"],
-  floors: HomeAssistant["floors"],
-  sensorNumericDeviceClasses: string[]
+  floors: HomeAssistant["floors"]
 ): Promise<{
  formatEntityState: FormatEntityStateFunc;
  formatEntityStateToParts: FormatEntityStateToPartsFunc;
@@ -66,25 +65,9 @@ export const computeFormatFunctions = async (

  return {
    formatEntityState: (stateObj, state) =>
-      computeStateDisplay(
-        localize,
-        stateObj,
-        locale,
-        sensorNumericDeviceClasses,
-        config,
-        entities,
-        state
-      ),
+      computeStateDisplay(localize, stateObj, locale, config, entities, state),
    formatEntityStateToParts: (stateObj, state) =>
-      computeStateToParts(
-        localize,
-        stateObj,
-        locale,
-        sensorNumericDeviceClasses,
-        config,
-        entities,
-        state
-      ),
+      computeStateToParts(localize, stateObj, locale, config, entities, state),
    formatEntityAttributeValue: (stateObj, attribute, value) =>
      computeAttributeValueDisplay(
        localize,
@@ -0,0 +1,58 @@
+import type { HassServiceTarget } from "home-assistant-js-websocket";
+import {
+  createQueryString,
+  decodeQueryParams,
+  queryParamsFromServiceTarget,
+  serviceTargetFromQueryParams,
+  type QueryParamConfig,
+  type QueryParamValues,
+  type SearchParamsSource,
+} from "./query-params";
+
+export type HistoryLogbookTargetParamKey =
+  | "entity_id"
+  | "label_id"
+  | "floor_id"
+  | "area_id"
+  | "device_id";
+
+export const historyLogbookTargetParamKeys: readonly HistoryLogbookTargetParamKey[] =
+  ["entity_id", "label_id", "floor_id", "area_id", "device_id"];
+
+export const historyLogbookQueryParamConfig = {
+  list: historyLogbookTargetParamKeys,
+  date: ["start_date", "end_date"],
+  boolean: [{ key: "back", trueValue: "1" }],
+} as const satisfies QueryParamConfig;
+
+export type HistoryLogbookQueryParams = QueryParamValues<
+  typeof historyLogbookQueryParamConfig
+>;
+
+export const decodeHistoryLogbookQueryParams = (
+  searchParams: SearchParamsSource
+): HistoryLogbookQueryParams =>
+  decodeQueryParams(searchParams, historyLogbookQueryParamConfig);
+
+export const historyLogbookTargetFromQueryParams = (
+  params: HistoryLogbookQueryParams
+): HassServiceTarget | undefined =>
+  serviceTargetFromQueryParams(params, historyLogbookTargetParamKeys);
+
+export const createHistoryLogbookUrl = (
+  path: string,
+  target: HassServiceTarget,
+  startDate: Date,
+  endDate: Date
+): string => {
+  const queryString = createQueryString(
+    {
+      ...queryParamsFromServiceTarget(target, historyLogbookTargetParamKeys),
+      start_date: startDate,
+      end_date: endDate,
+    },
+    historyLogbookQueryParamConfig
+  );
+
+  return queryString ? `${path}?${queryString}` : path;
+};
@@ -0,0 +1,172 @@
+import type { HassServiceTarget } from "home-assistant-js-websocket";
+import { ensureArray } from "../array/ensure-array";
+
+export type SearchParamsSource =
+  | URLSearchParams
+  | Record<string, string>
+  | string;
+
+export interface QueryParamConfig {
+  list?: readonly string[];
+  date?: readonly string[];
+  boolean?: readonly {
+    key: string;
+    trueValue: string;
+  }[];
+  string?: readonly string[];
+}
+
+type ListKeyOf<C extends QueryParamConfig> = C extends {
+  list: readonly (infer K extends string)[];
+}
+  ? K
+  : never;
+
+type DateKeyOf<C extends QueryParamConfig> = C extends {
+  date: readonly (infer K extends string)[];
+}
+  ? K
+  : never;
+
+type BooleanKeyOf<C extends QueryParamConfig> = C extends {
+  boolean: readonly { key: infer K extends string }[];
+}
+  ? K
+  : never;
+
+type StringKeyOf<C extends QueryParamConfig> = C extends {
+  string: readonly (infer K extends string)[];
+}
+  ? K
+  : never;
+
+export type QueryParamValues<C extends QueryParamConfig> = Partial<
+  Record<ListKeyOf<C>, string[]> &
+    Record<DateKeyOf<C>, Date> &
+    Record<BooleanKeyOf<C>, boolean> &
+    Record<StringKeyOf<C>, string>
+>;
+
+type QueryParamValue = string[] | Date | boolean | string;
+
+export type ServiceTargetQueryParams<
+  Key extends keyof HassServiceTarget & string,
+> = Partial<Record<Key, string[]>>;
+
+const getSearchParam = (
+  searchParams: SearchParamsSource,
+  key: string
+): string | null => {
+  if (typeof searchParams === "string") {
+    return new URLSearchParams(searchParams).get(key);
+  }
+  if (searchParams instanceof URLSearchParams) {
+    return searchParams.get(key);
+  }
+  return searchParams[key] ?? null;
+};
+
+export function decodeQueryParams<C extends QueryParamConfig>(
+  searchParams: SearchParamsSource,
+  config: C
+): QueryParamValues<C>;
+export function decodeQueryParams(
+  searchParams: SearchParamsSource,
+  config: QueryParamConfig
+): Record<string, QueryParamValue | undefined> {
+  const params: Record<string, QueryParamValue> = {};
+  for (const key of config.list ?? []) {
+    const value = getSearchParam(searchParams, key);
+    if (value) {
+      params[key] = value.split(",");
+    }
+  }
+  for (const key of config.date ?? []) {
+    const value = getSearchParam(searchParams, key);
+    if (value) {
+      params[key] = new Date(value);
+    }
+  }
+  for (const { key, trueValue } of config.boolean ?? []) {
+    if (getSearchParam(searchParams, key) === trueValue) {
+      params[key] = true;
+    }
+  }
+  for (const key of config.string ?? []) {
+    const value = getSearchParam(searchParams, key);
+    if (value) {
+      params[key] = value;
+    }
+  }
+  return params;
+}
+
+export function createQueryString<C extends QueryParamConfig>(
+  values: QueryParamValues<NoInfer<C>>,
+  config: C
+): string;
+export function createQueryString(
+  values: Record<string, QueryParamValue | undefined>,
+  config: QueryParamConfig
+): string {
+  const searchParams = new URLSearchParams();
+  for (const key of config.list ?? []) {
+    const value = values[key];
+    if (Array.isArray(value) && value.length) {
+      searchParams.append(key, value.join(","));
+    }
+  }
+  for (const key of config.date ?? []) {
+    const value = values[key];
+    if (value instanceof Date) {
+      searchParams.append(key, value.toISOString());
+    }
+  }
+  for (const { key, trueValue } of config.boolean ?? []) {
+    if (values[key]) {
+      searchParams.append(key, trueValue);
+    }
+  }
+  for (const key of config.string ?? []) {
+    const value = values[key];
+    if (typeof value === "string" && value) {
+      searchParams.append(key, value);
+    }
+  }
+  return searchParams.toString();
+}
+
+export const serviceTargetFromQueryParams = <
+  Key extends keyof HassServiceTarget & string,
+>(
+  params: ServiceTargetQueryParams<Key>,
+  keys: readonly Key[]
+): HassServiceTarget | undefined => {
+  if (!keys.some((key) => params[key])) {
+    return undefined;
+  }
+  const target: HassServiceTarget = {};
+  for (const key of keys) {
+    const value = params[key];
+    if (value) {
+      target[key] = value;
+    }
+  }
+  return target;
+};
+
+export const queryParamsFromServiceTarget = <
+  Key extends keyof HassServiceTarget & string,
+>(
+  target: HassServiceTarget,
+  keys: readonly Key[]
+): ServiceTargetQueryParams<Key> => {
+  const params: ServiceTargetQueryParams<Key> = {};
+  for (const key of keys) {
+    const value = target[key];
+    if (value) {
+      params[key] = ensureArray(value);
+    }
+  }
+  return params;
+};
--- a/Show More
+++ b/Show More