小编Rab*_*ara的帖子

    *{
    	margin: 0;
    	padding: 0;
    }
    
    .container{
    	height: 638px;
    	width: 100%;
    	max-width: 100%;
    	position: absolute;
    	overflow: hidden;
    	background-position: center;
    	top: 0;
    	z-index: -1;
    }
    
    .container img{
    	width: 100%;
    	height: 638px;
    }
    
    .container #short-des{
    	background: rgba(0,0,0,.5);
    	height: 400px;
    	width: 500px;
    	position: relative; 
    }

    	<div class="container">
    	<img src="cover.jpg">
    	<div id="short-des">
    	
    </div>
    </div>