Added shadows to the Bar, Menus, OSD and Notifications. (#777)

* Added shadows to the Bar, Menus and notifications.

* Add OSD shadows

src/components/menus/shared/dropdown/index.tsx

@@ -3,7 +3,7 @@ import { DropdownMenuProps } from 'src/lib/types/dropdownmenu';
 import { BarEventMargins } from './eventBoxes/index';
 import { globalEventBoxes } from 'src/globals/dropdown';
 import { bind } from 'astal';
-import { App, Astal, Gdk } from 'astal/gtk3';
+import { App, Astal, Gdk, Gtk } from 'astal/gtk3';
 import { Revealer } from 'astal/gtk3/widget';
 import { locationMap } from 'src/lib/types/defaults/bar';
 
@@ -88,7 +88,7 @@ export default ({
                                 transitionType={transition}
                                 transitionDuration={bind(options.menus.transitionTime)}
                             >
-                                <box className="dropdown-menu-container" canFocus>
+                                <box className="dropdown-content" halign={Gtk.Align.CENTER} expand canFocus>
                                     {child}
                                 </box>
                             </revealer>