<head>
<meta charset="UTF-8">
<title>图片文字遮罩</title>
<style type="text/css">
.box{
width: 200px;
height: 300px;
margin: 50px auto 0;
border: 1px solid #000;
position: relative;
/*默认文字不可见*/
overflow: hidden;
}
.box img{
width: 200px;
height: 300px;
}
.box .pic_info{
width: 200px;
height: 200px;
background-color: rgba(0,0,0,0.5);
color: #fff;
/*定位使色块在图片正下方*/
position: absolute;
left: 0;
top: 300px;
transition: all 500ms cubic-bezier(0.470, -0.485, 0.460, 1.435);
}
.box:hover .pic_info{
/*色块上移*/
top:150px;
}
/*间距用p标签的margin，而不直接给.pic_info用padding，因为padding会改变盒子大小*/
.box .pic_info p{
margin: 20px;
line-height: 30px;
}
</style>
</head>
<body>
<div class="box">
<img src="img/location_bg.jpg" alt="玫瑰花">
<div class="pic_info">
<p>图片说明：这是一朵玫瑰花图片说明：这是一朵玫瑰花图片说明：这是一朵玫瑰花图片说明：这是一朵玫瑰花</p>
</div>
</div>
</body>
###：在设置定位是注意要将父元素的相对定位打开
