Updated topbar button styles.

src/styles/components/_bar.scss

@@ -112,8 +112,8 @@
     top: 2px;
   }
   .btn {
-    background: transparent;
+    background: $bar-btn-action-normal;
-    border-color: transparent;
+    border-color: $bar-btn-action-normal-border;
     color: $bar-btn-action-color;
     height: 42px;
     font: 24px/40px $font-sans-serif;

src/styles/global/_variables.scss

@@ -80,6 +80,8 @@ $bar-btn-action-color: #333 !default;
 $bar-btn-action-hover: #666 !default;
 $bar-btn-action-mute: $action-mute !default;
 $bar-btn-action-enable: $action-enable !default;
+$bar-btn-action-normal: #e9e9e9 !default;
+$bar-btn-action-normal-border: #e2e2e2 !default;
 
 // overlaybar
 $overlaybar-background: $componentfg3;