/* 引入公共组件 */
@import url('components.css');

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

.main {
    margin-top: 140px;
    min-height: calc(100vh - 140px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    gap: 3rem;
}

.content-main {
    flex: 1;
    max-width: 800px;
}

.sidebar {
    width: 350px;
    flex-shrink: 0;
}

/* 章节样式 */
.section {
    margin-bottom: 3rem;
}

.section h1 {
    font-size: 2.2rem;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 1rem;
    border-bottom: 2px solid #2d3748;
    padding-bottom: 0.5rem;
}

.section h2 {
    font-size: 1.8rem;
    color: #2d3748;
    margin-bottom: 1rem;
    font-weight: 600;
}

.section h3 {
    font-size: 1.4rem;
    color: #2d3748;
    margin-bottom: 1rem;
    font-weight: 600;
}

.section-intro {
    font-size: 1.1rem;
    color: #4a5568;
    line-height: 1.6;
    margin-bottom: 2rem;
}

/* 英雄区域 */
.hero-section {
    background: #2563eb;
    color: white;
    padding: 140px 20px 100px;
    text-align: center;
    position: relative;
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-section::before {
    display: none;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    color: white;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2.5rem;
    color: rgba(255,255,255,0.95);
    font-weight: 400;
    letter-spacing: 0.3px;
}

.hero-description {
    font-size: 1.3rem;
    line-height: 1.8;
    margin-bottom: 3.5rem;
    color: rgba(255,255,255,0.9);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    font-weight: 400;
}

.cta-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

.cta-btn {
    padding: 14px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    font-size: 1.1rem;
    border: 2px solid transparent;
    min-width: 160px;
    text-align: center;
}

.cta-btn.primary {
    background: white;
    color: #2563eb;
    border-color: white;
}

.cta-btn.secondary {
    background: transparent;
    color: white;
    border-color: white;
}

.cta-btn.primary:hover {
    background: rgba(255,255,255,0.9);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}

.cta-btn.secondary:hover {
    background: rgba(255,255,255,0.1);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}

/* 研究方向 */
.research-intro h3 {
    font-size: 1.6rem;
    color: #2d3748;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.research-card {
    background: #ffffff;
    padding: 1.5rem;
    border-radius: 6px;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.research-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.research-icon {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #2d3748;
}

.research-card h3 {
    margin-bottom: 1rem;
    color: #2d3748;
    font-weight: 600;
}

.research-card ul {
    list-style: disc;
    padding-left: 1.5rem;
    color: #4a5568;
    line-height: 1.6;
}

.research-card li {
    margin-bottom: 0.5rem;
}

.research-card li:last-child {
    margin-bottom: 0;
}

.quick-links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.quick-link-card {
    background: #ffffff;
    padding: 1.5rem;
    border-radius: 6px;
    border: 1px solid #e2e8f0;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.quick-link-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.quick-link-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #2d3748;
}

.quick-link-card h3 {
    margin-bottom: 1rem;
    color: #2d3748;
    font-weight: 600;
}

.quick-link-card p {
    color: #4a5568;
    font-size: 0.9rem;
    margin: 0;
}

.news-section {
    margin-top: 3rem;
}

.news-list {
    margin-top: 1.5rem;
}

.news-item {
    padding: 0.75rem 0;
    border-bottom: 1px solid #e2e8f0;
    font-size: 0.95rem;
}

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

.news-more {
    text-align: center;
    margin-top: 1rem;
}

.news-link {
    color: #2d3748;
    text-decoration: none;
    font-weight: 600;
}

.news-link:hover {
    text-decoration: underline;
}

.contact-info {
    margin-top: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.contact-label {
    font-weight: 600;
    min-width: 60px;
    color: #4a5568;
}

.qr-section {
    margin-top: 2rem;
    text-align: center;
}

.qr-text {
    font-size: 0.9rem;
    color: #4a5568;
    margin-bottom: 1rem;
}

.qr-placeholder {
    width: 120px;
    height: 120px;
    background: #f7fafc;
    border-radius: 6px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #718096;
    font-size: 0.8rem;
}

.publications {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.publication-item {
    background: #ffffff;
    padding: 1.5rem;
    border-radius: 6px;
    border-left: 4px solid #2d3748;
    transition: all 0.3s ease;
    cursor: pointer;
    display: flex;
    gap: 1.5rem;
    align-items: stretch;
    min-height: 120px;
    border: 1px solid #e2e8f0;
}

.publication-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    border-left-color: #1a365d;
}

.publication-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 100px;
}

.publication-cover {
    flex-shrink: 0;
    width: 80px;
    border-radius: 4px;
    overflow: hidden;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    display: flex;
    align-items: stretch;
}

.cover-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    transition: transform 0.3s ease;
    background-color: #f8fafc;
}

.cover-image:hover {
    transform: scale(1.05);
}

.publication-links {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.doi-link,
.cover-link {
    padding: 0.4rem 0.8rem;
    background: #2d3748;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.8rem;
    transition: background 0.3s ease;
}

.doi-link:hover,
.cover-link:hover {
    background: #1a365d;
}

.publication-item h3 {
    color: #2d3748;
    margin-bottom: 0.5rem;
    line-height: 1.3;
    font-size: 1rem;
    font-weight: 600;
}

.publication-item p {
    color: #4a5568;
    margin-bottom: 0.5rem;
    font-style: italic;
    font-size: 0.9rem;
}

.publication-meta {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    flex-wrap: wrap;
}

.publication-journal {
    background: #2d3748;
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.publication-year {
    background: #e53e3e;
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.publication-doi {
    color: #4a5568;
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

.publication-doi a {
    color: #2d3748;
    text-decoration: underline;
}

.publication-doi a:hover {
    color: #1a365d;
}

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

.tool-item {
    background: #ffffff;
    padding: 1.5rem;
    border-radius: 6px;
    border-left: 4px solid #e53e3e;
    transition: all 0.3s ease;
    margin-bottom: 2rem;
    border: 1px solid #e2e8f0;
}

.tool-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.tool-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.tool-header h3 {
    color: #2d3748;
    margin: 0;
    font-weight: 600;
}

.tool-type {
    background: #e53e3e;
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.tool-description {
    color: #4a5568;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.tool-features {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.feature-tag {
    background: #f7fafc;
    color: #2d3748;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.tool-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 1rem;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 1.3rem;
    font-weight: bold;
    color: #2d3748;
    display: block;
}

.stat-label {
    font-size: 0.8rem;
    color: #4a5568;
    margin-top: 0.5rem;
}

.tool-links {
    display: flex;
    gap: 1rem;
}

.tool-link {
    padding: 0.4rem 0.8rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    font-size: 0.8rem;
}

.tool-link.primary {
    background: #2d3748;
    color: white;
}

.tool-link.primary:hover {
    background: #1a365d;
}

.tool-link.secondary {
    background: #f7fafc;
    color: #2d3748;
    border: 1px solid #e2e8f0;
}

.tool-link.secondary:hover {
    background: #edf2f7;
}

.tool-link.disabled {
    background: #e2e8f0;
    color: #a0aec0;
    cursor: not-allowed;
}

.team-members {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.member-card {
    background: #ffffff;
    padding: 1.5rem;
    border-radius: 6px;
    border-left: 4px solid #d69e2e;
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.member-card.featured {
    border-left-color: #e53e3e;
    background: #f7fafc;
}

.member-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.member-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.member-avatar {
    flex-shrink: 0;
}

.avatar-placeholder {
    width: 60px;
    height: 60px;
    background: #f7fafc;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: #4a5568;
}

.member-info h3 {
    color: #2d3748;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.member-title {
    color: #e53e3e;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.member-email {
    color: #4a5568;
    font-size: 0.9rem;
}

.member-bio {
    margin-bottom: 1rem;
}

.member-bio p {
    color: #4a5568;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.member-expertise {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.expertise-tag {
    background: #f7fafc;
    color: #2d3748;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.member-stats {
    display: flex;
    gap: 2rem;
}

.news-timeline {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.news-item {
    padding: 1rem;
    background: #ffffff;
    border-radius: 6px;
    border-left: 4px solid #2d3748;
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.news-item.featured {
    border-left-color: #e53e3e;
    background: #f7fafc;
}

.news-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.news-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.news-header h3 {
    font-size: 1rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    color: #2d3748;
}

.news-date {
    background: #2d3748;
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.news-content h3 {
    font-size: 1rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    color: #2d3748;
}

.news-content p {
    color: #4a5568;
    line-height: 1.6;
    margin-bottom: 0.5rem;
}

.news-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.news-category {
    background: #2d3748;
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.news-journal,
.news-platform {
    background: #f7fafc;
    color: #2d3748;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

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

.stat-item {
    text-align: center;
    padding: 1rem;
    background: #ffffff;
    border-radius: 6px;
    border: 1px solid #e2e8f0;
}

.stat-number {
    font-size: 1.8rem;
    font-weight: 700;
    color: #2d3748;
    display: block;
}

.stat-label {
    font-size: 0.9rem;
    color: #4a5568;
    margin-top: 0.5rem;
}

.research-areas,
.application-areas,
.categories,
.directions,
.institutions {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.research-area,
.application-area,
.category-item,
.direction-item,
.institution-item {
    background: #f7fafc;
    padding: 0.75rem 1rem;
    border-radius: 6px;
    color: #2d3748;
    font-weight: 600;
    transition: all 0.3s ease;
}

.research-area:hover,
.application-area:hover,
.category-item:hover,
.direction-item:hover,
.institution-item:hover {
    background: #2d3748;
    color: white;
    transform: translateX(5px);
}

.achievements {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.achievement-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: #ffffff;
    border-radius: 6px;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.achievement-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.achievement-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
    color: #2d3748;
}

.achievement-content h4 {
    color: #2d3748;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.achievement-content p {
    color: #4a5568;
    font-size: 0.9rem;
    line-height: 1.4;
}

.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    text-align: center;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f7fafc;
    border-top: 4px solid #2d3748;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-container p {
    color: #4a5568;
    font-size: 1.1rem;
}

.error-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    text-align: center;
    background: #fed7d7;
    border: 1px solid #feb2b2;
    border-radius: 6px;
    color: #c53030;
}

.error-container h2 {
    margin-bottom: 1rem;
    color: #c53030;
}

.error-container p {
    color: #742a2a;
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .cta-buttons {
        flex-direction: column;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .quick-links-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-stats {
        flex-direction: column;
    }
    
    .member-stats {
        flex-direction: column;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-links {
        flex-direction: column;
    }
    
    .news-meta {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    /* 论文卡片移动端适配 */
    .publication-item {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .publication-cover {
        width: 100%;
        height: 120px;
        order: -1;
    }
    
    .publication-content {
        min-height: auto;
    }
    
    .publication-links {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .doi-link,
    .cover-link {
        text-align: center;
    }
}

/* 更新header样式以匹配MIT风格 */
.header {
    background: #2563eb;
    color: white;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(37, 99, 235, 0.3);
    height: 120px;
    display: flex;
    flex-direction: column;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
}

.header-title {
    text-align: center;
    margin-bottom: 1rem;
}

.header-title h1 {
    font-size: 1.8rem;
    margin: 0;
    font-weight: 700;
}

.header-subtitle {
    font-size: 1rem;
    opacity: 0.9;
    margin-top: 0.25rem;
    display: block;
}

/* 确保导航栏样式正确应用 */
.nav {
    background: rgba(255,255,255,0.05);
    width: 100%;
    display: flex;
    justify-content: center;
    border-top: 1px solid rgba(255,255,255,0.15);
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 3rem;
    width: 100%;
}

.nav-links {
    display: flex;
    gap: 2rem;
    justify-content: center;
    align-items: center;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 8px 12px;
    border-radius: 6px;
    transition: all 0.3s ease;
    font-weight: 500;
    position: relative;
    font-size: 0.9rem;
}

.nav-link:hover,
.nav-link.active {
    background: rgba(255,255,255,0.2);
    color: white;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 3px;
    background: white;
    border-radius: 2px;
}

.join-btn {
    background: white;
    color: #2563eb;
    padding: 8px 16px;
    border-radius: 6px;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.join-btn:hover {
    background: rgba(255,255,255,0.9);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}