绝对定位来实现 block 水平垂直居中 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <title>Document</title>
    <style>
        .big{
            position: relative;
            width: 1000px;
            height: 1000px;
            border: 1px solid red;
        }
        .sml{
            /*通过定位来达到水平垂直居中*/
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            width: 400px;
            height: 400px;
            border: 1px solid green;
            margin: auto;
        }
    </style>
</head>
<body>
    <div class="big">
        <div class="sml">
            
        </div>
    </div>
</body>
</html>

 

posted @ 2016-09-13 17:08  nostic  阅读(103)  评论(0)  编辑  收藏  举报