Update index_menu.htm

src/admin/templets/index_menu.htm

@@ -51,7 +51,8 @@
 			}
 			a.mm:hover div {
 				color: #fff;
-				background: #424b51
+				background: #424b51;
+				transition: all .2s
 			}
 			dl.bitem {
 				margin: 1rem 0 10px 0;