/* 导航栏样式 */
.header {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: var(--transition);
    height: 70px;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    cursor: pointer;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transition: width 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

/* 首页横幅 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 120px 20px;
    text-align: center;
    margin-top: 70px;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 80%;
        max-width: 300px;
        height: calc(100vh - 70px);
        background: var(--bg-white);
        flex-direction: column;
        padding: 2rem 0;
        box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
        transition: left 0.3s ease;
        z-index: 999;
        gap: 0;
    }

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

    .nav-menu li {
        width: 100%;
    }

    .nav-menu a {
        display: block;
        padding: 1rem 2rem;
        border-bottom: 1px solid var(--border-color);
    }

    .logo {
        font-size: 1.2rem;
    }

    .menu-toggle {
        display: block !important;
    }
    
    .hero {
        padding: 80px 20px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
}