Fixed #189

src/sass/gnome-shell/common/_app-grid.scss

@@ -11,6 +11,7 @@ $app_grid_fg_color: #fff;
     border-radius: $bd_radius * 1.5;
     padding: 8px;
     border: none;
+    transition-duration: 100ms;
     text-align: center;
   }
 

src/sass/gnome-shell/common/_looking-glass.scss

@@ -27,7 +27,9 @@
     padding-left: 16px;
     padding-right: 16px;
     min-height: $medium_size;
-    padding: 0 16px * 2;
+    padding: 0 32px;
+    transition-duration: 100ms;
+
     &:hover {
       box-shadow: inset 0 -2px 0px $track_color;
       color: $fg_color;

src/sass/gnome-shell/common/_panel.scss

@@ -12,6 +12,7 @@ $shell_panel_bg: if($trans == 'true', $panel_bg, rgba($panel_bg, 0.95));
   box-shadow: 0 5px 16px rgba(black, 0.35);
   color: $panel_fg;
   font-feature-settings: "tnum";
+  transition-duration: 250ms;
 
   // transparent panel on lock & login screens
   &:overview,
@@ -50,6 +51,7 @@ $shell_panel_bg: if($trans == 'true', $panel_bg, rgba($panel_bg, 0.95));
     -panel-corner-border-width: 2px;
     -panel-corner-border-color: transparent;
     -panel-corner-opacity: 1;
+    transition-duration: 250ms;
   }
 
   // panel menus
@@ -58,7 +60,7 @@ $shell_panel_bg: if($trans == 'true', $panel_bg, rgba($panel_bg, 0.95));
     -minimum-hpadding: 8px;
     font-weight: bold;
     color: $panel_fg;
-    // transition-duration: $longer_duration;
+    transition-duration: 150ms;
     border-radius: $bt_radius;
 
     StLabel { padding: 0 2px; }

src/sass/gnome-shell/widgets-3-28/_window-picker.scss

@@ -42,6 +42,7 @@ $_close_size: 42px;
   box-shadow: none;
   StIcon { icon-size: $_close_size; } // for safety
   background-image: url("assets/window-close.svg");
+  transition-duration: 300ms;
 
   &:hover {
     background-size: $_close_size;