代码示例：（标识：bs_utility_pb-responsive）
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/js/bootstrap.bundle.js"></script>
</head>
<body>
<div class="p-4">
<h1>下内边距 Utility</h1>
<div class="pb-0 bg-warning">Padding Bottom 0</div>
<div class="pb-1 bg-success">Padding Bottom 1</div>
<div class="pb-2 bg-danger">Padding Bottom 2</div>
<div class="pb-3 bg-primary">Padding Bottom 3</div>
<div class="pb-4 bg-light">Padding Bottom 4</div>
<div class="pb-5 bg-info">Padding Bottom 5</div>
<br>
<p>响应式下内边距实用工具。请调整浏览器窗口大小以查看效果：</p>
<div class="pb-sm-5 bg-warning">在 SM 屏幕上的 Padding Bottom 5</div>
<div class="pb-md-5 bg-success">在 MD 屏幕上的 Padding Bottom 5</div>
<div class="pb-lg-5 bg-danger">在 LG 屏幕上的 Padding Bottom 5</div>
<div class="pb-xl-5 bg-primary">在 XL 屏幕上的 Padding Bottom 5</div>
</div>
</body>
</html>
