Fix ha-card outline box shadow in firefox (#6174)

* Fix ha-card outline box shadow in firefox

* Add fallback for markdown code background

src/components/buttons/ha-progress-button.js

@@ -8,6 +8,9 @@ class HaProgressButton extends PolymerElement {
   static get template() {
     return html`
       <style>
+        :host {
+          outline: none;
+        }
         .container {
           position: relative;
           display: inline-block;

src/components/ha-card.ts

@@ -35,7 +35,7 @@ class HaCard extends LitElement {
       }
 
       :host([outlined]) {
-        box-shadow: 0 0 0 0;
+        box-shadow: none;
         border-width: 1px;
         border-style: solid;
         border-color: var(

src/components/ha-markdown.ts

@@ -54,7 +54,7 @@ class HaMarkdown extends LitElement {
       }
       ha-markdown-element code,
       pre {
-        background-color: var(--markdown-code-background-color, #f6f8fa);
+        background-color: var(--markdown-code-background-color, none);
         border-radius: 3px;
       }
       ha-markdown-element code {

src/resources/ha-style.ts

@@ -86,6 +86,9 @@ documentContainer.innerHTML = `<custom-style>
       /* set our slider style */
       --ha-paper-slider-pin-font-size: 15px;
 
+      /* markdown styles */
+      --markdown-code-background-color: #f6f8fa;
+
       /* rgb */
       --rgb-primary-color: 3, 169, 244;
       --rgb-accent-color: 255, 152, 0;