<a href="#">fadeTo</a>
<span>W3TR</span>
a{display: inline-block; background: #00FF99; padding:20px; border-bottom:4px solid #00CC00; color:#00CC99; text-decoration:none; margin-bottom:20px;}
span{display:block; font-size:30px; color:red; margin-bottom:20px;}
$("a").click(function(){
$("span").fadeTo(500, 0.3);
});
This Pen doesn't use any external CSS resources.