使用align-text-bottom类将元素与父元素字体的底部对齐。
您需要设置align-text-bottom类，如下所示-
<span class="align-text-bottom"> Bottom Text </span>
您可以尝试运行以下代码以在Bootstrap 4中实现align-text-bottom类-
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/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/4.1.0/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Example</h2> <p>This is demo text<p> <span class="align-baseline">Demo Baseline</span> <span class="align-top">Top Alignment</span> <span class="align-text-top">Top Text</span> <span class="align-text-bottom">Bottom Text</span> </div> </body> </html>