css set width by right code example

Example: increase width from right to left css

<div class="icon">
   test
</div>
<style>
	.icon{
      width: 128px;
      height: 128px;
      background: url(icons.png) no-repeat red;
      background-position: left top;
      -webkit-transition: width .2s;
      position:absolute;
      top:0; right:0; 
  }
  .icon:hover{
      width:250px
}
</style>