improved styles

examples/webgl_loader_imagebitmap.html

@@ -39,9 +39,11 @@
 				border: 1px solid white;
 				cursor: pointer;
 				white-space: nowrap;
+				user-select: none;
 			}
 			.actions span:hover{
 				color: red;
+				border-color: red;
 			}
 			.actions span:active{
 				color: black;