HTML的默认强调标记（例如<small>）将文本设置为父级大小的85％，<strong>强调具有较重字体重量的文本，而<em>则以斜体突出文本。
您可以尝试运行以下代码来强调文本-
<!DOCTYPE html> <html> <head> <title>Bootstrap emphasis tags</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script> </head> <body> <small>This content is within tag</small><br> <strong>This content is within tag</strong><br> <em>This content is within tag and is rendered as italics</em><br> <p class = "text-left">Left aligned text.</p> <p class = "text-center">Center aligned text.</p> <p class = "text-right">Right aligned text.</p> <p class = "text-muted">This content is muted</p> <p class = "text-primary">This content carries a primary class</p> <p class = "text-danger">This content carries a danger class</p> </body> </html>