Fixed preview button for mobile devices

Author: JulianPrieber

studio/button-editor/css/style.css

@@ -490,7 +490,6 @@ button-demo {
   text-align: center;
   vertical-align: middle;
   font-size: 18px;
-  width: 300px;
   font-weight: 700;
   line-height: 48px;
   letter-spacing: 0.1px;