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-
<!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>