html代码
<div class="user2-register-bg">
<div class="user2-register-con"> </div>
</div>
css代码
.user2-register-bg{padding: 10px;padding: 10px;background:rgba(0,0,0,0.3)!important;background:#;filter:Alpha(opacity=); margin-top: 30px;}
.user2-register-con{height:500px; background:#fff; position:relative; }
注意这两个位置