@media (max-width: 768px) {
    .main-nav {
        display: none;
        flex-direction: column;
        background: #fff;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    }

    .main-nav.active {
        display: flex;
    }

    .main-nav a {
        padding: 15px;
        text-align: center;
        border-top: 1px solid #eee;
    }

    .mobile-menu-icon {
        display: block;
    }
}