<!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.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">
<h1>阴影</h1>
<p>请使用 shadow- 类为元素添加阴影：</p>
<div class="shadow-none p-4 mb-4 bg-light">没有阴影</div>
<div class="shadow-sm p-4 mb-4 bg-white">小型阴影</div>
<div class="shadow p-4 mb-4 bg-white">默认阴影</div>
<div class="shadow-lg p-4 mb-4 bg-white">大型阴影</div>
</div>
</body>
</html>