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

:root {
    --primary-color: #e74c3c;
    --secondary-color: #c0392b;
    --accent-color: #e67e22;
    --dark-bg: #1a1a1a;
    --light-bg: #f8f9fa;
    --text-dark: #2c3e50;
    --text-light: #ecf0f1;
    --border-color: #ddd;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --gradient-1: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
    --gradient-2: linear-gradient(135deg, #e67e22 0%, #d35400 100%);
    --gradient-3: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    --gradient-4: linear-gradient(135deg, #9b59b6 0%, #8e44ad 100%);
    --gradient-5: linear-gradient(135deg, #1abc9c 0%, #16a085 100%);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: #fff;
}

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

.header {
    background: var(--gradient-1);
    color: var(--text-light);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo a {
    font-size: 28px;
    font-weight: bold;
    color: var(--text-light);
    text-decoration: none;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.nav ul {
    display: flex;
    list-style: none;
    gap: 5px;
}

.nav a {
    color: var(--text-light);
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 5px;
    transition: all 0.3s;
    font-size: 14px;
}

.nav a:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.hero {
    background: var(--gradient-1);
    color: var(--text-light);
    padding: 80px 0;
    text-align: center;
}

.hero h1 {
    font-size: 42px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero-subtitle {
    font-size: 18px;
    margin-bottom: 50px;
    opacity: 0.95;
}

.hero-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.feature-item {
    background: rgba(255,255,255,0.1);
    padding: 30px;
    border-radius: 10px;
    backdrop-filter: blur(10px);
    transition: all 0.3s;
}

.feature-item:hover {
    transform: translateY(-5px);
    background: rgba(255,255,255,0.15);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: var(--gradient-2);
    border-radius: 50%;
}

.feature-item h3 {
    font-size: 22px;
    margin-bottom: 10px;
}

section {
    padding: 80px 0;
}

section:nth-child(even) {
    background: var(--light-bg);
}

h2 {
    font-size: 36px;
    text-align: center;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.section-desc {
    text-align: center;
    font-size: 16px;
    color: #666;
    margin-bottom: 50px;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.card {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.card-image {
    width: 100%;
    height: 220px;
    background: var(--gradient-3);
}

.card:nth-child(2n) .card-image {
    background: var(--gradient-4);
}

.card:nth-child(3n) .card-image {
    background: var(--gradient-5);
}

.card:nth-child(4n) .card-image {
    background: var(--gradient-2);
}

.card-content {
    padding: 25px;
}

.card h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--text-dark);
    line-height: 1.4;
}

.card-meta {
    font-size: 13px;
    color: #999;
    margin-bottom: 15px;
}

.card-desc {
    font-size: 14px;
    color: #666;
    line-height: 1.8;
}

.content-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
}

.article-card {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.article-image {
    width: 100%;
    height: 300px;
    background: var(--gradient-1);
}

.article-content {
    padding: 30px;
}

.article-content h3 {
    font-size: 24px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.article-meta {
    font-size: 13px;
    color: #999;
    margin-bottom: 20px;
}

.article-content p {
    font-size: 15px;
    color: #666;
    line-height: 1.9;
}

.sidebar-widget {
    background: #fff;
    padding: 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.sidebar-widget h3 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--primary-color);
    text-align: left;
}

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

.topic-list li {
    margin-bottom: 12px;
}

.topic-list a {
    color: var(--text-dark);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.topic-list a:hover {
    color: var(--primary-color);
}

.comment-item {
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
}

.comment-item:last-child {
    border-bottom: none;
}

.comment-user {
    font-weight: bold;
    font-size: 14px;
    margin-bottom: 5px;
    color: var(--primary-color);
}

.comment-text {
    font-size: 13px;
    color: #666;
}

.timeline {
    position: relative;
    padding-left: 50px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--gradient-1);
}

.timeline-item {
    position: relative;
    margin-bottom: 50px;
}

.timeline-marker {
    position: absolute;
    left: -38px;
    top: 0;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 4px solid #fff;
    box-shadow: 0 0 0 3px var(--primary-color);
}

.timeline-content {
    background: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.timeline-content h3 {
    font-size: 22px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.timeline-date {
    font-size: 13px;
    color: #999;
    margin-bottom: 15px;
}

.timeline-content p {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
}

.news-list {
    max-width: 900px;
    margin: 0 auto;
}

.news-item {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.news-image {
    width: 100%;
    height: 350px;
    background: var(--gradient-2);
}

.news-content {
    padding: 30px;
}

.news-content h3 {
    font-size: 26px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.news-meta {
    font-size: 13px;
    color: #999;
    margin-bottom: 20px;
}

.news-content p {
    font-size: 15px;
    color: #666;
    line-height: 1.9;
}

.community-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.feature-box {
    background: #fff;
    padding: 40px 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: all 0.3s;
}

.feature-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.feature-icon-large {
    width: 100px;
    height: 100px;
    margin: 0 auto 25px;
    background: var(--gradient-1);
    border-radius: 50%;
}

.feature-box:nth-child(2) .feature-icon-large {
    background: var(--gradient-2);
}

.feature-box:nth-child(3) .feature-icon-large {
    background: var(--gradient-3);
}

.feature-box:nth-child(4) .feature-icon-large {
    background: var(--gradient-4);
}

.feature-box h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.feature-box p {
    font-size: 14px;
    color: #666;
    line-height: 1.8;
}

.community-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    background: var(--gradient-1);
    padding: 50px;
    border-radius: 15px;
}

.stat-item {
    text-align: center;
    color: var(--text-light);
}

.stat-number {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 16px;
    opacity: 0.9;
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 50px;
    background: #fff;
    padding: 50px;
    border-radius: 15px;
    box-shadow: var(--shadow);
}

.about-text h3 {
    font-size: 24px;
    margin: 30px 0 15px 0;
    color: var(--primary-color);
}

.about-text h3:first-child {
    margin-top: 0;
}

.about-text p {
    font-size: 15px;
    color: #666;
    line-height: 1.9;
    margin-bottom: 20px;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.about-feature-item {
    text-align: center;
}

.about-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 15px;
    background: var(--gradient-1);
    border-radius: 50%;
}

.about-feature-item:nth-child(2) .about-icon {
    background: var(--gradient-2);
}

.about-feature-item:nth-child(3) .about-icon {
    background: var(--gradient-3);
}

.about-feature-item:nth-child(4) .about-icon {
    background: var(--gradient-4);
}

.about-feature-item h4 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.about-feature-item p {
    font-size: 14px;
    color: #666;
}

.footer {
    background: var(--dark-bg);
    color: var(--text-light);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--text-light);
    text-align: left;
}

.footer-section p {
    font-size: 14px;
    line-height: 1.8;
    color: #bbb;
    margin-bottom: 10px;
}

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

.footer-section li {
    margin-bottom: 10px;
}

.footer-section a {
    color: #bbb;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: var(--primary-color);
}

.footer-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.footer-tags a {
    background: rgba(255,255,255,0.1);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 13px;
    transition: all 0.3s;
}

.footer-tags a:hover {
    background: var(--primary-color);
    color: #fff;
}

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

.footer-links {
    margin-bottom: 20px;
}

.footer-links a {
    color: #bbb;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

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

.footer-links span {
    margin: 0 10px;
    color: #666;
}

.footer-copyright {
    font-size: 13px;
    color: #888;
}

.footer-copyright p {
    margin-bottom: 10px;
}

.footer-copyright a {
    color: #888;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-copyright a:hover {
    color: var(--primary-color);
}

.footer-desc {
    max-width: 800px;
    margin: 20px auto 0;
    line-height: 1.8;
}

@media (max-width: 768px) {
    .nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .nav a {
        font-size: 12px;
        padding: 6px 10px;
    }
    
    .hero h1 {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-features {
        grid-template-columns: 1fr;
    }
    
    h2 {
        font-size: 28px;
    }
    
    .card-grid {
        grid-template-columns: 1fr;
    }
    
    .content-layout {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        padding: 30px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .community-stats {
        grid-template-columns: 1fr;
        padding: 30px;
    }
    
    .timeline {
        padding-left: 30px;
    }
    
    .timeline::before {
        left: 10px;
    }
    
    .timeline-marker {
        left: -28px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    section {
        padding: 50px 0;
    }
    
    .hero {
        padding: 50px 0;
    }
    
    .hero h1 {
        font-size: 24px;
    }
    
    .hero-subtitle {
        font-size: 14px;
    }
    
    h2 {
        font-size: 24px;
    }
    
    .card-content,
    .article-content,
    .news-content,
    .timeline-content {
        padding: 20px;
    }
    
    .feature-box {
        padding: 30px 20px;
    }
    
    .stat-number {
        font-size: 36px;
    }
}