简单教程
提交运行
代码编辑器：
<meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="/static/lib/bootstrap/4.0.0/css/bootstrap.min.css"> <script src="/static/lib/jquery/3.3.1/jquery.min.js"></script> <script src="/static/lib/bootstrap/4.0.0/js/bootstrap.min.js"></script> <style> span { display: inline-block; width: 70px; height: 70px; margin: 6px; background-color: #555; } </style> <div class="container"> <p>.rounded 和 .rounded-* 可以用来设置圆角边框和圆形边框</p> <span class="rounded"></span> <span class="rounded-top"></span> <span class="rounded-right"></span> <span class="rounded-bottom"></span> <span class="rounded-left"></span> <span class="rounded-circle"></span> <span class="rounded-0"></span> </div>
运行结果：