上传按钮美化

<input type="file" name="file" id="file" class="inputfile" />
<label for="file">Choose a file</label>

.inputfile {
    width: 0.1px; 
    height: 0.1px; 
   filter:alpha(opacity=0);
   -moz-opacity:0;
    opacity: 0; 
    overflow: hidden; 
    position: absolute; 
    z-index: -1;
}

.inputfile + label { font-size: 1.25em; font-weight: 700; color: white; background-color: black; display: inline-block; pointer-events: none;}

.inputfile:focus + label, .inputfile + label:hover { background-color: red; }

.inputfile:focus + label {
    outline: 1px dotted #000; 
    outline: -webkit-focus-ring-color auto 5px; //Chrome/Opera/Safari上的一个默认支持的小技巧
}

http://www.jianshu.com/p/07c27e576b26