Fix menu without background

Author: c4software

archlinux/install/tilling/config/waybar/style.css

@@ -122,4 +122,9 @@ tooltip {
 #battery.critical:not(.charging) {
     color: #f53c3c;
     animation: blink 0.5s linear infinite alternate;
-}
+}
+
+menu {
+    background-color: @background;
+    opacity: 1.0;
+}