<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap 实例</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">
<h2>删除边框</h2>
<p>使用 .list-group-flush 类可删除边框和圆角：</p>
</div>
<div class="container mt-3">
<ul class="list-group list-group-flush">
<li class="list-group-item">第一项</li>
<li class="list-group-item">第二项</li>
<li class="list-group-item">第三项</li>
<li class="list-group-item">第四项</li>
</ul>
</div>
</body>
</html>