/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 科技感深色主题配色 */
    --bg-dark: #05060d;
    --bg-darker: #030314;
    --bg-card: rgba(9, 15, 33, 0.75);
    --bg-card-light: rgba(14, 24, 52, 0.65);
    --bg-glass: rgba(255, 255, 255, 0.08);

    --primary-color: #3d7fff;
    --secondary-color: #38f18a;
    --accent-color: #23d8f8;
    --accent-purple: #8e61ff;
    --dark-color: #05060d;
    --light-color: rgba(255, 255, 255, 0.08);

    --text-color: rgba(255, 255, 255, 0.75);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.75);
    --text-muted: rgba(255, 255, 255, 0.55);

    --border-color: rgba(255, 255, 255, 0.1);

    --gradient-1: linear-gradient(135deg, #1a45ff, #23d8f8);
    --gradient-2: linear-gradient(135deg, #8e61ff, #f093fb);
    --gradient-3: linear-gradient(135deg, #23d8f8, #38f18a);
    --gradient-primary: linear-gradient(135deg, #1a45ff, #23d8f8);

    --shadow: 0 18px 40px rgba(8, 16, 46, 0.4);
    --shadow-lg: 0 10px 28px rgba(6, 12, 28, 0.35);
    --shadow-card: 0 18px 40px rgba(8, 16, 46, 0.4);

    --radius-lg: 28px;
    --radius-md: 20px;
    --radius-sm: 14px;
}

body {
    font-family: 'Urbanist', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-dark);
    position: relative;
    overflow-x: hidden;
}

/* 页面渐变背景 */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    z-index: -1;
    background: radial-gradient(circle at 20% 20%, rgba(61, 127, 255, 0.35), transparent 45%),
                radial-gradient(circle at 80% 10%, rgba(142, 97, 255, 0.28), transparent 50%),
                radial-gradient(circle at 60% 80%, rgba(35, 216, 248, 0.18), transparent 60%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(5, 6, 13, 0.88);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    box-shadow: var(--shadow);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(5, 6, 13, 0.95);
    box-shadow: var(--shadow-lg);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.logo img {
    height: 40px;
    width: auto;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

.lang-switch {
    padding: 0.5rem 1rem;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
    background: rgba(61, 127, 255, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
}

.lang-switch:hover {
    background: rgba(61, 127, 255, 0.2);
    box-shadow: 0 0 15px rgba(61, 127, 255, 0.3);
    color: var(--primary-color);
    transform: translateY(-2px);
}

.lang-switch::after {
    display: none;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    transition: all 0.3s ease;
}

/* 英雄区 */
.hero {
    position: relative;
    height: 100vh;
    overflow: hidden;
    margin-top: 70px;
}

.hero-slider {
    position: relative;
    height: 100%;
}

.hero-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    opacity: 0;
    transition: opacity 1s ease;
}

.hero-slide.active {
    opacity: 1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.3));
}

.hero-content {
    position: relative;
    z-index: 10;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: white;
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    opacity: 0.95;
}

.hero-desc {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    max-width: 600px;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    border: 2px solid var(--primary-color);
}

.btn-primary:hover {
    background: transparent;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-outline:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
}

.hero-nav {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 20;
}

.hero-nav-btn {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.hero-nav-btn.active,
.hero-nav-btn:hover {
    background: white;
    transform: scale(1.2);
}

.scroll-indicator {
    position: absolute;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    color: white;
    font-size: 2rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* 动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    animation: fadeIn 1s ease;
}

.animate-fade-in-delay {
    animation: fadeIn 1s ease 0.3s both;
}

.animate-fade-in-delay-2 {
    animation: fadeIn 1s ease 0.6s both;
}

.animate-fade-in-delay-3 {
    animation: fadeIn 1s ease 0.9s both;
}

/* 通用区块样式 */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    text-shadow: 0 0 20px rgba(61, 127, 255, 0.3);
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 800px;
    margin: 0 auto;
}

/* 关于我们 */
.about {
    background: transparent;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    margin-bottom: 4rem;
}

.about-text {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.info-card {
    display: flex;
    gap: 1.5rem;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: var(--shadow-card);
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.info-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    min-width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
    border-radius: 12px;
}

.info-content h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.info-content p {
    color: var(--text-secondary);
    line-height: 1.8;
}

.small-text {
    font-size: 0.95rem;
}

.about-image {
    position: relative;
}

.about-image img {
    width: 100%;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
}

.about-badge {
    position: absolute;
    bottom: 20px;
    right: 20px;
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
}

.badge-content {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.badge-content i {
    font-size: 2rem;
    color: var(--accent-color);
}

.badge-content strong {
    font-size: 1.2rem;
    color: var(--primary-color);
    display: block;
}

.badge-content span {
    font-size: 0.9rem;
    color: var(--text-color);
}

/* 统计数据 */
.stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.stat-card {
    text-align: center;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: var(--shadow-card);
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: rgba(61, 127, 255, 0.5);
}

.stat-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* 核心优势 */
.advantages {
    background: transparent;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.advantage-card {
    position: relative;
    padding: 2.5rem 2rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    text-align: center;
    transition: all 0.3s ease;
    overflow: hidden;
}

.advantage-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.advantage-card:hover::before {
    transform: scaleX(1);
}

.advantage-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(61, 127, 255, 0.5);
}

.advantage-number {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 3rem;
    font-weight: 800;
    color: rgba(0, 0, 0, 0.05);
}

.advantage-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.advantage-card h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 700;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.advantage-card p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.advantage-en {
    font-size: 0.85rem;
    color: var(--accent-color);
    font-weight: 600;
}

/* 服务与支持 */
.services {
    background: transparent;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-bottom: 4rem;
}

.service-card {
    padding: 2.5rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: var(--shadow-card);
    transition: all 0.3s ease;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(61, 127, 255, 0.5);
}

.service-icon {
    width: 70px;
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-1);
    border-radius: 15px;
    font-size: 2rem;
    color: white;
    margin-bottom: 1.5rem;
}

.service-card:nth-child(2) .service-icon {
    background: var(--gradient-2);
}

.service-card:nth-child(3) .service-icon {
    background: var(--gradient-3);
}

.service-card:nth-child(4) .service-icon {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

.service-card h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 700;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.service-en {
    font-size: 0.9rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    display: block;
}

.service-list {
    list-style: none;
}

.service-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.service-list li:last-child {
    border-bottom: none;
}

.service-list i {
    color: var(--secondary-color);
}

/* 支持保障 */
.support-section {
    background: var(--bg-card);
    padding: 3rem;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-card);
}

.support-title {
    text-align: center;
    font-size: 1.8rem;
    color: var(--text-primary);
    margin-bottom: 2rem;
    font-weight: 700;
}

.support-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.support-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-card-light);
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.support-item i {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-top: 0.25rem;
}

/* 资质认证 */
.qualifications {
    background: transparent;
}

.qualifications-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 1.5rem;
}

.qualification-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    transition: all 0.3s ease;
    cursor: pointer;
}

.qualification-card:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
    border-color: rgba(61, 127, 255, 0.5);
}

.qualification-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* 新闻动态 */
.news {
    background: transparent;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.news-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    transition: all 0.3s ease;
}

.news-card.featured {
    grid-column: span 2;
    grid-row: span 2;
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(61, 127, 255, 0.5);
}

.news-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.news-card.featured .news-image {
    height: 300px;
}

.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.news-card:hover .news-image img {
    transform: scale(1.1);
}

.news-badge {
    position: absolute;
    top: 15px;
    left: 15px;
    background: var(--accent-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.news-content {
    padding: 1.5rem;
}

.news-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    color: #6b7280;
}

.news-meta span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.news-content h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    line-height: 1.4;
    font-weight: 700;
}

.news-card.featured .news-content h3 {
    font-size: 1.5rem;
}

.news-content p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.news-excerpt {
    display: block;
}

.news-full-content {
    margin-top: 1rem;
}

.news-full-content p {
    margin-bottom: 1rem;
}

.news-card.expanded .news-excerpt {
    display: none;
}

.news-card.expanded .news-full-content {
    display: block !important;
}

.news-card.expanded .news-link i {
    transform: rotate(90deg);
}

.news-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: gap 0.3s ease, color 0.3s ease;
}

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

.news-link:hover {
    gap: 1rem;
}

/* 团队展示 */
.team {
    background: transparent;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.team-card {
    text-align: center;
    transition: transform 0.3s ease;
}

.team-card:hover {
    transform: translateY(-10px);
}

.team-image {
    width: 100%;
    height: 250px;
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-card);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.team-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.team-card:hover .team-image img {
    transform: scale(1.1);
}

.team-info h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    font-weight: 700;
}

.team-info p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.team-desc {
    color: var(--accent-color) !important;
    font-weight: 600;
}

/* 联系我们 */
.contact {
    background: transparent;
}

.contact-cards-wrapper {
    max-width: 1000px;
    margin: 0 auto;
}

.contact-main-card {
    text-align: center;
    padding: 3rem;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 3rem;
}

.contact-main-card h3 {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.contact-en {
    color: var(--accent-color);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.contact-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 2rem;
    background: var(--gradient-primary);
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
}

.contact-badge i {
    font-size: 1.3rem;
}

.contact-cards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.contact-card {
    text-align: center;
    padding: 2rem 1.5rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all 0.3s ease;
}

.contact-card:hover {
    transform: translateY(-5px);
    border-color: rgba(61, 127, 255, 0.5);
    box-shadow: var(--shadow-lg);
}

.contact-card-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    font-size: 1.5rem;
}

.contact-card h4 {
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.contact-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.social-section {
    text-align: center;
    padding: 2.5rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.social-section h4 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.social-links a {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border-radius: 50%;
    text-decoration: none;
    font-size: 1.3rem;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.social-links a:hover {
    background: var(--gradient-primary);
    transform: translateY(-5px) scale(1.1);
    border-color: transparent;
    box-shadow: 0 10px 25px rgba(61, 127, 255, 0.4);
}

/* 页脚 */
.footer {
    background: var(--bg-darker);
    color: var(--text-primary);
    padding: 4rem 0 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h4 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.footer-badge {
    display: inline-block;
    background: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.75rem;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: white;
}

.footer-social {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-social a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        padding: 2rem;
        transition: left 0.3s ease;
    }

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

    .hamburger {
        display: flex;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .stats {
        grid-template-columns: repeat(2, 1fr);
    }

    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .support-grid {
        grid-template-columns: 1fr;
    }

    .qualifications-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .news-grid {
        grid-template-columns: 1fr;
    }

    .news-card.featured {
        grid-column: span 1;
        grid-row: span 1;
    }

    .team-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.3rem;
    }

    .hero-desc {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .stats {
        grid-template-columns: 1fr;
    }

    .advantages-grid {
        grid-template-columns: 1fr;
    }

    .qualifications-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .team-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}