<title>Bootstrap 实例 - 居中内容块</title>
<link rel="stylesheet" href="/css/bootstrap/bootstrap3.3.7.min.css">
<script src="/js/bootstrap/jquery.min.js"></script>
<script src="/js/bootstrap/bootstrap3.3.7.min.js"></script>
<div class="center-block" style="width:200px;background-color:#ccc;">