<html>
<head>
<title>test</title>
<style>
.form-element-file-wapper {
position: relative;
width: 100px;
height: 32px;
overflow: hidden;
margin: 0 auto;
}
.form-element-file-wapper button {
width: 100px;
height: 32px;
background-color: #38ADFF;
color: #fff;
}
.form-element-file-wapper input[type=file] {
position: absolute;
top: 0;
left: 0;
width: 100px;
height: 32px;
opacity: 0;
cursor: pointer;
font-size: 500px;
}
</style>
</head>
<body>
<div class="form-element-file-wapper">
<button type="button">上传照片</button>
<input type="file" accept="image/jpeg,image/png,image/gif">
</div>
</body>
</html>
原文：http://www.cnblogs.com/chenweichu/p/5593312.html