上拉菜单js

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Pull-up Menu Example</title>
    <style>
        body {
            margin: 0;
            font-family: Arial, sans-serif;
        }
        .menu {
            position: fixed;
            bottom: 0;
            left: 0;
            width: 100%;
            background-color: #333;
            color: white;
            transform: translateY(100%);
            transition: transform 0.3s ease-in-out;
        }
        .menu.active {
            transform: translateY(0);
        }
        .content {
            padding: 20px;
        }
    </style>
</head>
<body>
    <div class="content">
        <h1>Main Content</h1>
        <p>Scroll up to see the menu.</p>
    </div>
    <div class="menu" id="menu">
        <ul>
            <li>Option 1</li>
            <li>Option 2</li>
            <li>Option 3</li>
        </ul>
    </div>

    <script>
        let startY = 0;
        const menu = document.getElementById('menu');

        document.addEventListener('touchstart', (e) => {
            startY = e.touches[0].clientY;
        });

        document.addEventListener('touchmove', (e) => {
            const currentY = e.touches[0].clientY;
            const diff = currentY - startY;

            if (diff > 0 && window.scrollY === 0) {
                menu.style.transform = `translateY(${Math.min(diff, 100)}%)`;
            }
        });

        document.addEventListener('touchend', () => {
            if (menu.style.transform === 'translateY(100%)') {
                menu.classList.remove('active');
            } else {
                menu.classList.add('active');
            }
        });
    </script>
</body>
</html>