jquery 导航栏固定

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Fixed Navbar Example</title>
    <style>
        body {
            margin: 0;
            font-family: Arial, sans-serif;
        }
        .navbar {
            background-color: #333;
            overflow: hidden;
            position: relative;
        }
        .navbar a {
            float: left;
            display: block;
            color: #f2f2f2;
            text-align: center;
            padding: 14px 20px;
            text-decoration: none;
        }
        .navbar a:hover {
            background-color: #ddd;
            color: black;
        }
        .content {
            padding: 16px;
        }
    </style>
</head>
<body>

<div class="navbar">
    <a href="#home">Home</a>
    <a href="#news">News</a>
    <a href="#contact">Contact</a>
    <a href="#about">About</a>
</div>

<div class="content">
    <h1>Scroll Down</h1>
    <p>Scroll down to see the fixed navbar in action.</p>
    <!-- Add more content here -->
</div>

<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script>
    $(document).ready(function() {
        var navbar = $('.navbar');
        var sticky = navbar.offset().top;

        $(window).scroll(function() {
            if ($(window).scrollTop() >= sticky) {
                navbar.addClass('sticky');
            } else {
                navbar.removeClass('sticky');
            }
        });
    });
</script>

</body>
</html>