Update style.css

Author: JulianPrieber

studio/button-editor/css/style.css

@@ -490,6 +490,7 @@ button-demo {
   text-align: center;
   vertical-align: middle;
   font-size: 18px;
+  min-width: 200px;
   font-weight: 700;
   line-height: 48px;
   letter-spacing: 0.1px;