html中input type=file 改变样式

<style>  
#uploadImg{ font-size:12px; overflow:hidden; position:absolute}  
#file{ position:absolute; z-index:100; margin-left:-180px; font-size:60px;opacity:0;filter:alpha(opacity=0); margin-top:-5px;}  
</style>  
  
<span id="uploadImg">  
<input type="file" id="file" size="1" >  
<a href="#">上传图片</a> </span>