相对和绝对的使用

 

<!-- HTML结构 -->
<div class="news-group">
<form action="" class="edit_item">
<div class="news-lists">
<p>标题标题标题</p>
<div class="cover">
<img src="xxxxx/57d8e6c60571a.jpg" alt="" />
</div>
</div>
<div class="hidden-action">
<a href="javascript:void(0)">编辑</a>
<a href="javascript:void(0)">删除</a>
</div>
</form>
</div>
 
<!-- CSS -->
<style>
.news-group .edit_item{
position: relative;
}
 
.news-group .hidden-action{
background: RGBA(0,0,0,.4);
position: absolute;
z-index: 99;
top: 0;
bottom: 0;
left: 0;
right: 0;
}
</style>