sidebery: add audio animation in audio playing tabs

addons/sidebery-styles.css

@@ -64,6 +64,29 @@
   --toolbar-bg: #202020;
 }
 
+/* Add animation to icon shown when playing audio in a tab */
+.Tab .-loud {
+  animation: audio-animation 1.2s infinite ease-in-out;
+}
+
+@keyframes audio-animation {
+  0% {
+    transform: scale(0.9);
+  }
+  25% {
+    transform: scale(1.1);
+  }
+  50% {
+    transform: scale(1.2);
+  }
+  75% {
+    transform: scale(1.1);
+  }
+  100% {
+    transform: scale(0.9);
+  }
+}
+
 /* Based on: https://raw.githubusercontent.com/mgastonportillo/gale-for-ff/main/sidebery.css */
 #root {
   --tabs-height: 34px;

readme.md

@@ -36,6 +36,7 @@ My tailor-fitted, highly customized, and advanced [Firefox](https://www.mozilla.
 - Compact about:config list
 - Compact items and menus (e.g., context menu)
 - Various sidebar (Sidebery, Tree Style Tab) tweaks, including auto-hide
+- Animations in tabs that's playing audio
 - Consistent and matching colors across various elements and the UI
 - Glow and scale effect on hover on toolbar buttons
 - Findbar as floating box at the top