Add checkmark on top of status icon buttons when they are active (#1783)

app/javascript/flavours/glitch/styles/accessibility.scss

@@ -12,6 +12,21 @@ $emojis-requiring-inversion: 'back' 'copyright' 'curly_loop' 'currency_exchange'
   }
 }
 
+// Display a checkmark on active UI elements otherwise differing only by color
+.status__action-bar-button,
+.detailed-status__button .icon-button {
+  position: relative;
+
+  &.active::after {
+    position: absolute;
+    content: "\F00C";
+    font-size: 50%;
+    font-family: FontAwesome;
+    right: -5px;
+    top: -4px;
+  }
+}
+
 .hicolor-privacy-icons {
   .status__visibility-icon.fa-globe,
   .composer--options--dropdown--content--item .fa-globe {