<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.2/dist/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.2/dist/js/bootstrap.bundle.min.js"></script>
</head>
<body>
<div class="container mt-3">
<h2>加载器</h2>
<p>如需创建 spinner/加载器，请使用 <code>.spinner-border</code> 类：</p>
<div class="spinner-border"></div>
</div>
</body>
</html>