JSFiddle - React, Tailwind, and code Playground
HTML
<ul>
<li><a href="#" class="fbhover"></a>
</li>
</ul>
CSS
.fbhover{
display: inline-block;
background-image: url('http://i.imgur.com/nHJ6Loa.png');
background-repeat:no-repeat;
height: 27px;
width: 26px;
}
.fbhover:hover {
background-image:url(http://i.imgur.com/bdMNHnw.png);
}