<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="https://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script>
<script src="https://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h1>h1 Bootstrap heading <small>(36px)</small></h1>
<h2>h2 Bootstrap heading <small>(30px)</small></h2>
<h3>h3 Bootstrap heading <small>(24px)</small></h3>
<h4>h4 Bootstrap heading <small>(18px)</small></h4>
<h5>h5 Bootstrap heading <small>(14px)</small></h5>
<h6>h6 Bootstrap heading <small>(12px)</small></h6>
</div>
</body>
</html>