开源教程在线编辑器

<!DOCTYPE html>
<html>
<head>
  <title>Bootstrap 实例</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css">
  <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
  <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script>
  <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script>
</head>
<body style="height:1500px">

<div class="container-fluid">
  <h3>底部固定导航栏</h3>
  <p>导航栏可以固定在头部或者底部。</p>
  <h1>滚动页面查看效果。</h1>
</div>

</body>
</html>