JSFiddle - React, Tailwind, and code Playground

HTML

<a href="http://facebook.com"></a>

CSS

a[href="http://facebook.com"] {
    background: url("https://raw.github.com/danleech/simple-icons/master/icons/facebook/facebook-128-black.png") no-repeat;
	width: 128px;
	height: 128px;
	opacity: .5;
    display: inline-block;
}

a[href="http://facebook.com"]:hover{
	opacity: 1.0;
}