/* 导航栏样式 */
header {
    background-color: var(--light-color);
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-text span {
    color: var(--primary-color);
}

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

.nav-item {
    margin: 0 15px;
    position: relative;
}

.nav-link {
    font-weight: 600;
    color: var(--dark-color);
    transition: color 0.3s;
    padding: 10px 0;
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background-color: var(--primary-color);
    transition: width 0.3s;
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background-color: var(--dark-color);
    transition: all 0.3s;
}

@media (max-width: 768px) {
    .hamburger {
        display: block;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 80px;
        gap: 0;
        flex-direction: column;
        background-color: var(--light-color);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
        padding: 20px 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-item {
        margin: 15px 0;
    }
}