JSFiddle - React, Tailwind, and code Playground

HTML

<button class="btn"><i class="icon"></i></button>
<button class="btn"><i class="icon icon-small"></i></button>
<button class="btn"><i class="icon icon-small-resized"></i></button>

CSS

button::-moz-focus-inner {
	border: 0;
	padding: 0;
}

.btn, .btn-small{
	border:0;
	background:#000;
	padding:5px;
	margin:5px;
}

.icon{
	width:50px;
	height:50px;
	background-image:url(https://ssl.gstatic.com/gb/images/v1_53a1fa6a.png);
    background-position: -145px -75px;
	background-repeat:no-repeat;
	display:inline-block;

}

.icon-small{
	zoom:0.5;
    -moz-transform:scale(0.5);
    -moz-transform-origin: 0 0;
}

.icon-small-resized{
	width:25px;
	height:25px;
    zoom:0.5;
    -moz-transform:scale(0.5);
    -moz-transform-origin: 0 0;
}