html+css实现自定义图片上传按钮

<label class="btn">
<span>选择图片</span>
<input type="file" />
</label>

.btn{
display: inline-block;
width: 75px;
height: 25px;
line-height: 25px;
border: 1px solid #23c6c8;
background: #23c6c8;
color: #fff;
text-align: center;
font-size: 14px;
border-radius: 3px;
overflow: hidden;
position: relative;
vertical-align: center;
}
.btn:hover{
border: 1px solid #23babc;
background: #23BABC;
}
input{
position: absolute;
left: 0;
top: 0;
opacity: 0;
}