<label class="input">
<input title="浏览文件" type="file" />浏览…
</label>
<style type="text/css">
.input{display: inline-block;
width: 140px;
height: 50px;
line-height: 50px;
text-align: center;
overflow: hidden;
position: relative;
background-color: #00a1cb;
color: #fafafa;
text-shadow:0 -1px 0 rgba(0,0,0,0.25);
border-radius: 1px;
transition:background .3s;
-webkit-transition:background .3s}/*自定义外框样式*/
.input:hover{background-color: #00b5e5}/*鼠标经过样式*/
.input input{opacity: 0;filter:alpha(opacity=0);
font-size: 100px;
position: absolute;
top: 0;
right: 0} /*隐藏默认控件样式*/
</style>
原文：http://www.cnblogs.com/roves/p/4923335.html