JSFiddle - React, Tailwind, and code Playground

HTML

<button>Click me to toggle loading class on the button</button>
<br /><br/>
<a href="#">button</a>

CSS

a {
	padding: 8px 10px;
	transition: background-color 0.5s linear;
	-moz-transition: background-color 0.5s linear;
	-webkit-transition: background-color 0.5s linear;
	cursor: pointer;
	border-radius: 2px;
	-moz-border-radius: 2px;
	-webkit-border-radius: 2px;
	-o-border-radius: 2px;	
	text-align: center;
	color: #eee;
	border: 0px;
	background-color: #333;
	background-repeat: repeat-x;
}

a.loading {
	background-color: #bbb;
	background-position: 0 -15px;
	transition: background-color 0.5s linear;
	-moz-transition: background-color 0.5s linear;
	-webkit-transition: background-color 0.5s linear;
}

JavaScript

$(document).ready(function(){
  $("button").click(function(){
    $("a").toggleClass("loading");
  });
});