input file文件上传样式

<style>
.file-group {
position: relative;
width: 200px;
height: 80px;
border: 1px solid #ccc; /* 为了显示可见区域，非必须 */
overflow: hidden;
cursor: pointer;
line-height: 80px;
font-size: 16px;
text-align: center;
color: #fff;
background-color: #f50;
border-radius: 4px;
}
.file-group input {
position: absolute;
right: 0;
top: 0;
font-size: 300px;
opacity: 0;
filter: alpha(opacity=0);
cursor: pointer;
}
.file-group:hover {
background-color: #f60;
}
</style>
<div class="file-group">
<input type="file" name="" id="J_File">
选择文件
</div>