W3School TIY Editor

<!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-fluid mt-3">
  <h3>Offcanvas 侧栏</h3>
  <p>Offcanvas 类似于模态，不同之处在于它经常用作侧边栏。</p>
  <button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#demo">
    打开 Offcanvas 侧栏
  </button>
</div>

</body>
</html>