/* 移动端导航样式 */
@media screen and (max-width: 768px) {
    .nav-menu {
        display: none;
        position: fixed;
        top: 60px;
        left: 0;
        width: 100%;
        background: #fff;
        box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        z-index: 1000;
    }

    .nav-menu.active {
        display: block;
    }

    .nav-menu ul {
        flex-direction: column;
        padding: 20px 0;
    }

    .nav-menu li {
        margin: 0;
        padding: 10px 20px;
    }
}