手机站左侧导航js

<div class="sidebar">
    <ul>
        <li><a href="#">Home</a></li>
        <li class="dropdown">
            <a href="#" class="dropbtn">Services</a>
            <div class="dropdown-content">
                <a href="#">Service 1</a>
                <a href="#">Service 2</a>
                <a href="#">Service 3</a>
            </div>
        </li>
        <li><a href="#">About</a></li>
    </ul>
</div>
<button onclick="toggleSidebar()">Toggle Sidebar</button>

.sidebar {
    height: 100%;
    width: 250px;
    position: fixed;
    z-index: 1;
    top: 0;
    left: -250px;
    background-color: #111;
    overflow-x: hidden;
    transition: 0.5s;
}

.sidebar ul {
    padding: 0;
}

.sidebar a {
    padding: 8px 8px 8px 32px;
    text-decoration: none;
    font-size: 25px;
    color: #818181;
    display: block;
    transition: 0.3s;
}

.sidebar a:hover {
    color: #f1f1f1;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
}

.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}

.dropdown:hover .dropdown-content {
    display: block;
}

function toggleSidebar() {
    var sidebar = document.querySelector('.sidebar');
    if (sidebar.style.left === '-250px') {
        sidebar.style.left = '0';
    } else {
        sidebar.style.left = '-250px';
    }
}