Bootstrap中的内联子标题
要将内联子标题添加到任何标题，只需在任何元素周围添加<small>或添加.small类，您将获得颜色较浅的较小文本。
您可以尝试运行以下代码以在Bootstrap中使用内联子标题-
示例
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<h1>Heading1 h1.
<small>I'm secondary Heading h1</small>
</h1>
<h2>Heading2 h2.
<small>I'm secondary Heading h2</small>
</h2>
</body>
</html>