/* 导航栏 */
nav {
    background-color: var(--primary-color);
    position: relative;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-menu {
    display: flex;
    list-style: none;
}

.nav-menu>li {
    position: relative;
}

.nav-menu>li>a {
    color: var(--dark);
    text-decoration: none;
    padding: 18px 22px;
    display: block;
    transition: all 0.3s;
    font-weight: 600;
    font-size: 16px;
    position: relative;
}

.nav-menu>li>a:hover {
    color: var(--text-color);
    background-color: var(--primary-color-light);
}

.nav-menu>li>a:hover::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--accent);
}

/* 二级菜单样式 */
.sub-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 220px;
    background: var(--primary-color);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    list-style: none;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
    z-index: 999;
    border-top: 3px solid var(--accent);
}

.nav-menu>li:hover .sub-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.sub-menu li a {
    display: block;
    padding: 12px 20px;
    color: var(--dark);
    text-decoration: none;
    transition: all 0.3s;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    font-size: 15px;
}

.sub-menu li a:hover {
    background-color: var(--primary-color-light);
    color: var(--text-color);
    padding-left: 25px;
}

.sub-menu li a i {
    margin-right: 8px;
    color: var(--accent);
}

@media (max-width: 768px) {
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav-menu>li>a {
        padding: 15px;
        font-size: 15px;
    }
}