Small style adjustments in the labels AB test.

services/web/public/stylesheets/app/editor/toolbar.less

@@ -141,7 +141,8 @@
 	display: inline-block;
 	margin: 0 4px;
 	font-size: 12px;
-	font-weight: normal;
+	font-weight: 600;
+	margin-bottom: 2px;
 	vertical-align: middle;
 }