mpris: allow CSS control of album art icon size

data/style/widgets/mpris.scss

@@ -28,11 +28,11 @@
 
     .mpris-overlay {
       background: var(--dialog-bg-color);
-      padding: 5px;
+      padding: 10px;
 
       .widget-mpris-album-art {
         border-radius: var(--window-radius);
-        margin: 3px;
+        margin: 0px;
         box-shadow: none;
         -gtk-icon-size: var(--mpris-album-art-icon-size);
       }
@@ -47,7 +47,8 @@
       }
 
       .image-button {
-        padding: 0px 5px;
+        padding: 0;
+        margin: 0;
 
         &:hover {
           background: unquote("alpha(var(--window-bg-color), 0.3)");

data/ui/widgets/mpris_player.blp

@@ -27,7 +27,6 @@ template $XimperShellNotificationCenterWidgetsMprisMprisPlayer: $Underlay {
       Image album_art {
         icon-name: "audio-x-generic-symbolic";
         use-fallback: true;
-        pixel-size: 96;
         overflow: hidden;
 
         styles [