1<div class="icon">
2 test
3</div>
4<style>
5 .icon{
6 width: 128px;
7 height: 128px;
8 background: url(icons.png) no-repeat red;
9 background-position: left top;
10 -webkit-transition: width .2s;
11 position:absolute;
12 top:0; right:0;
13 }
14 .icon:hover{
15 width:250px
16}
17</style>