:root {
    --primary-color: #ff6b6b;
    --secondary-color: #4ecdc4;
    --accent-color: #ffe66d;
    --dark-bg: #2c3e50;
    --light-bg: #ecf0f1;
    --text-dark: #2c3e50;
    --text-light: #ffffff;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --card-shadow-hover: 0 8px 16px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --border-radius: 12px;
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

#header {
    background: var(--dark-bg);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

.navbar {
    padding: var(--spacing-sm) 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-light);
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: bold;
    transition: var(--transition);
}

.logo:hover {
    color: var(--primary-color);
    transform: scale(1.05);
}

.logo i {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    color: var(--text-light);
    text-decoration: none;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: var(--transition);
    font-weight: 500;
}

.nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--accent-color);
    transform: translateY(-2px);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-light);
    font-size: 1.5rem;
    cursor: pointer;
}

#content {
    min-height: calc(100vh - 80px);
    padding: var(--spacing-lg) 0;
}

.loader {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 400px;
    gap: var(--spacing-sm);
}

.loader-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: var(--spacing-xl) 0;
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    color: var(--text-light);
    text-align: center;
    box-shadow: var(--card-shadow);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: moveBackground 20s linear infinite;
}

@keyframes moveBackground {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-section h1 {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-section p {
    font-size: 1.3rem;
    opacity: 0.95;
}

.section-title {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
    color: var(--dark-bg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.section-title i {
    color: var(--primary-color);
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.video-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    cursor: pointer;
}

.video-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--card-shadow-hover);
}

.video-thumbnail {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

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

.video-info {
    padding: var(--spacing-sm);
}

.video-title {
    font-size: 1.1rem;
    font-weight: bold;
    margin-bottom: var(--spacing-xs);
    color: var(--text-dark);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-description {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: var(--spacing-xs);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: #999;
    margin-top: var(--spacing-sm);
}

.video-category {
    display: inline-block;
    padding: 4px 12px;
    background: var(--secondary-color);
    color: white;
    border-radius: 20px;
    font-size: 0.8rem;
    margin-bottom: var(--spacing-xs);
}

.video-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-xs);
}

.video-tag {
    padding: 2px 8px;
    background: var(--light-bg);
    border-radius: 4px;
    font-size: 0.75rem;
    color: #666;
}

.video-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.video-list-item {
    display: flex;
    gap: var(--spacing-md);
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    cursor: pointer;
}

.video-list-item:hover {
    box-shadow: var(--card-shadow-hover);
    transform: translateX(8px);
}

.video-list-thumbnail {
    width: 250px;
    height: 150px;
    object-fit: cover;
    flex-shrink: 0;
}

.video-list-info {
    padding: var(--spacing-sm);
    flex: 1;
}

.carousel-section {
    margin-bottom: var(--spacing-xl);
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
}

.carousel-container {
    position: relative;
    overflow: hidden;
}

.carousel-track {
    display: flex;
    gap: var(--spacing-md);
    transition: transform 0.5s ease;
}

.carousel-item {
    min-width: 300px;
    flex-shrink: 0;
}

.carousel-button {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0, 0, 0, 0.5);
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    z-index: 10;
}

.carousel-button:hover {
    background: rgba(0, 0, 0, 0.8);
}

.carousel-button.prev {
    left: 10px;
}

.carousel-button.next {
    right: 10px;
}

.masonry-grid {
    column-count: 3;
    column-gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.masonry-item {
    break-inside: avoid;
    margin-bottom: var(--spacing-lg);
}

.video-detail {
    max-width: 1200px;
    margin: 0 auto;
}

.video-player-container {
    background: #000;
    border-radius: var(--border-radius);
    overflow: hidden;
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--card-shadow-hover);
}

.video-player {
    width: 100%;
    aspect-ratio: 16/9;
    display: block;
}

.video-detail-info {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    margin-bottom: var(--spacing-lg);
}

.video-detail-title {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--dark-bg);
}

.video-detail-meta {
    display: flex;
    gap: var(--spacing-md);
    color: #666;
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.video-detail-description {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #555;
    margin-bottom: var(--spacing-md);
}

.video-review {
    background: linear-gradient(135deg, #ffeaa7 0%, #fdcb6e 100%);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-top: var(--spacing-md);
}

.video-review h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--dark-bg);
}

.video-review p {
    line-height: 1.8;
    color: var(--text-dark);
}

.related-videos {
    margin-top: var(--spacing-xl);
}

.search-container {
    max-width: 800px;
    margin: 0 auto var(--spacing-xl);
}

.search-box {
    display: flex;
    gap: var(--spacing-sm);
    background: white;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
}

.search-input {
    flex: 1;
    padding: var(--spacing-sm);
    border: 2px solid var(--light-bg);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.search-button {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: var(--transition);
}

.search-button:hover {
    background: #ff5252;
    transform: scale(1.05);
}

.info-page {
    max-width: 900px;
    margin: 0 auto;
    background: white;
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
}

.info-page h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--dark-bg);
    border-bottom: 3px solid var(--primary-color);
    padding-bottom: var(--spacing-sm);
}

.info-page h2 {
    font-size: 1.8rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--secondary-color);
}

.info-page h3 {
    font-size: 1.4rem;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    color: var(--dark-bg);
}

.info-page p {
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    color: #555;
}

.info-page ul {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.info-page li {
    margin-bottom: var(--spacing-xs);
    line-height: 1.8;
}

.contact-info {
    background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin: var(--spacing-lg) 0;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
}

.contact-item i {
    color: var(--primary-color);
    font-size: 1.3rem;
}

.timeline {
    position: relative;
    padding-left: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--secondary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-lg);
    padding-left: var(--spacing-lg);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -10px;
    top: 5px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 3px solid white;
    box-shadow: var(--card-shadow);
}

.timeline-year {
    font-size: 1.3rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.error-page {
    text-align: center;
    padding: var(--spacing-xl);
    max-width: 600px;
    margin: 0 auto;
}

.error-page h1 {
    font-size: 6rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.error-page h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.error-page p {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: var(--spacing-lg);
}

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: var(--transition);
    font-weight: bold;
}

.btn:hover {
    background: #ff5252;
    transform: translateY(-2px);
    box-shadow: var(--card-shadow);
}

#footer {
    background: var(--dark-bg);
    color: var(--text-light);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--accent-color);
}

.footer-section p {
    opacity: 0.9;
    margin-bottom: var(--spacing-sm);
}

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

.footer-section li {
    margin-bottom: var(--spacing-xs);
}

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    opacity: 0.8;
    transition: var(--transition);
}

.footer-section a:hover {
    opacity: 1;
    color: var(--accent-color);
    padding-left: var(--spacing-xs);
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.8;
}

.footer-bottom p {
    margin: var(--spacing-xs) 0;
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 999;
}

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

.back-to-top:hover {
    background: #ff5252;
    transform: translateY(-5px);
}

@media (max-width: 1024px) {
    .masonry-grid {
        column-count: 2;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        background: var(--dark-bg);
        flex-direction: column;
        padding: var(--spacing-md);
        transition: var(--transition);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
    }

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

    .mobile-menu-toggle {
        display: block;
    }

    .hero-section h1 {
        font-size: 2rem;
    }

    .hero-section p {
        font-size: 1rem;
    }

    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: var(--spacing-md);
    }

    .video-list-item {
        flex-direction: column;
    }

    .video-list-thumbnail {
        width: 100%;
        height: 200px;
    }

    .masonry-grid {
        column-count: 1;
    }

    .carousel-item {
        min-width: 250px;
    }

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

    .video-detail-title {
        font-size: 1.5rem;
    }

    .info-page {
        padding: var(--spacing-md);
    }

    .info-page h1 {
        font-size: 2rem;
    }

    .error-page h1 {
        font-size: 4rem;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
    }

    .carousel-item {
        min-width: 200px;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease;
}

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

.category-header {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    color: white;
    text-align: center;
}

.category-header h1 {
    font-size: 2.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.no-results {
    text-align: center;
    padding: var(--spacing-xl);
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
}

.no-results i {
    font-size: 4rem;
    color: #ccc;
    margin-bottom: var(--spacing-md);
}

.no-results h2 {
    color: #666;
    margin-bottom: var(--spacing-sm);
}