/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #1976d2;
    --secondary: #42a5f5;
    --accent: #64b5f6;
    --dark: #0d47a1;
    --bg-light: #f5f5f5;
    --bg-white: #ffffff;
    --text-dark: #212121;
    --text: #424242;
    --text-light: #757575;
    --border: #e0e0e0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
}

/* 顶部导航栏 */
.top-header {
    background: var(--bg-white);
    border-bottom: 2px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.header-wrapper {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 30px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo-area {
    display: flex;
    align-items: baseline;
    gap: 12px;
}

.site-logo {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.site-tagline {
    font-size: 14px;
    color: var(--text-light);
    font-weight: 500;
}

.top-nav {
    flex: 1;
    display: flex;
    justify-content: center;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-item {
    color: var(--text-dark);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
    transition: color 0.3s;
}

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

.nav-item.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary);
    border-radius: 2px;
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 3px;
    transition: all 0.3s;
}

/* 主容器 */
.main-wrapper {
    max-width: 1600px;
    margin: 0 auto;
    padding: 30px;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 30px;
    align-items: start;
}

/* 侧边栏 */
.sidebar {
    position: sticky;
    top: 90px;
    background: var(--bg-white);
    border-radius: 12px;
    padding: 25px;
    box-shadow: var(--shadow);
    height: fit-content;
}

.sidebar-content {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.sidebar-section {
    border-bottom: 1px solid var(--border);
    padding-bottom: 25px;
}

.sidebar-section:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.sidebar-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary);
}

.sidebar-menu {
    list-style: none;
}

.sidebar-menu li {
    margin-bottom: 10px;
}

.sidebar-menu a {
    color: var(--text);
    text-decoration: none;
    font-size: 15px;
    padding: 8px 12px;
    display: block;
    border-radius: 6px;
    transition: all 0.3s;
}

.sidebar-menu a:hover,
.sidebar-menu a.active {
    background: var(--primary);
    color: var(--bg-white);
}

.sidebar-ad {
    width: 100%;
    border-radius: 8px;
    overflow: hidden;
}

.sidebar-ad img {
    width: 100%;
    height: auto;
    display: block;
}

/* 主内容区 */
.main-content {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 0;
    box-shadow: var(--shadow);
    overflow: hidden;
}

/* 横幅区域 */
.hero-section {
    position: relative;
    width: 100%;
    height: 400px;
    overflow: hidden;
}

.hero-image {
    width: 100%;
    height: 100%;
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.6));
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-text {
    text-align: center;
    color: var(--bg-white);
    padding: 0 30px;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.hero-subtitle {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--accent);
    font-weight: 500;
}

.hero-desc {
    font-size: 18px;
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto;
}

/* 内容区块 */
.content-section {
    padding: 50px 40px;
}

.section-header {
    margin-bottom: 35px;
    padding-bottom: 20px;
    border-bottom: 3px solid var(--primary);
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-dark);
}

.section-body {
    font-size: 17px;
    line-height: 1.9;
    color: var(--text-dark);
}

.section-body p {
    margin-bottom: 25px;
}

.section-body p:last-child {
    margin-bottom: 0;
}

/* 视频网格 */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
}

.video-card {
    background: var(--bg-light);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s;
    cursor: pointer;
}

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

.video-thumb {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--text-dark);
}

.video-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.video-card:hover .video-thumb img {
    transform: scale(1.1);
}

.play-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s;
}

.video-card:hover .play-overlay {
    opacity: 1;
}

.play-icon {
    font-size: 48px;
    color: var(--bg-white);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.video-info {
    padding: 20px;
}

.video-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.video-meta {
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 10px;
}

.video-desc {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* 特色网格 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.feature-item {
    text-align: center;
    padding: 30px 20px;
    background: var(--bg-light);
    border-radius: 12px;
    transition: all 0.3s;
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid var(--primary);
}

.feature-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.feature-heading {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.feature-text {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.6;
}

/* 页面标题 */
.page-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    padding: 50px 40px;
    color: var(--bg-white);
    text-align: center;
}

.page-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 12px;
}

.page-subtitle {
    font-size: 18px;
    opacity: 0.9;
}

/* 服务列表 */
.services-list {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.service-item {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 25px;
    padding: 30px;
    background: var(--bg-light);
    border-radius: 12px;
    transition: all 0.3s;
}

.service-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow);
}

.service-icon {
    width: 120px;
    height: 120px;
    border-radius: 12px;
    overflow: hidden;
    border: 3px solid var(--primary);
}

.service-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.service-content {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.service-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.service-desc {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-light);
}

/* 关于内容 */
.about-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 40px;
    align-items: start;
}

.about-text h2 {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 25px;
}

.about-text p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--text-dark);
    margin-bottom: 20px;
}

.about-image {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.about-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* 联系内容 */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.contact-text h2 {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 25px;
}

.contact-text p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--text-dark);
    margin-bottom: 30px;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-row {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 20px;
    background: var(--bg-light);
    border-radius: 8px;
}

.contact-label {
    font-size: 14px;
    color: var(--text-light);
    font-weight: 500;
}

.contact-value {
    font-size: 16px;
    color: var(--text-dark);
    font-weight: 600;
}

.contact-image {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.contact-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* 信息内容 */
.info-content {
    background: var(--bg-light);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
}

.info-content h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 20px;
}

.info-content p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--text-light);
}

/* 页脚 */
.main-footer {
    background: var(--text-dark);
    color: var(--bg-white);
    padding: 60px 0 20px;
    margin-top: 50px;
}

.footer-wrapper {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 50px;
    margin-bottom: 50px;
}

.footer-heading {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 25px;
    color: var(--accent);
}

.footer-text {
    font-size: 15px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.7);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 15px;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .main-wrapper {
        grid-template-columns: 240px 1fr;
        gap: 20px;
    }
}

@media (max-width: 1024px) {
    .main-wrapper {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
        display: none;
    }

    .sidebar.active {
        display: block;
        margin-bottom: 20px;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        background: var(--bg-white);
        flex-direction: column;
        padding: 30px;
        gap: 0;
        box-shadow: var(--shadow-lg);
        transition: left 0.3s;
        z-index: 99;
    }

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

    .nav-menu li {
        width: 100%;
        border-bottom: 1px solid var(--border);
    }

    .nav-item {
        display: block;
        padding: 15px 0;
    }

    .mobile-toggle {
        display: flex;
    }

    .mobile-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .mobile-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 36px;
    }

    .section-title {
        font-size: 28px;
    }

    .content-section {
        padding: 30px 20px;
    }

    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 15px;
    }

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

@media (max-width: 480px) {
    .hero-title {
        font-size: 28px;
    }

    .page-title {
        font-size: 32px;
    }

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