/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 根变量定义 - 学术风格配色 */
:root {
    --primary-color: #1a365d;
    --secondary-color: #4a5568;
    --accent-color: #2b6cb0;
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --background-light: #f7fafc;
    --background-white: #ffffff;
    --background-paper: #fefefe;
    --border-color: #e2e8f0;
    --border-light: #edf2f7;
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px 0 rgb(0 0 0 / 0.06);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -1px rgb(0 0 0 / 0.06);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -2px rgb(0 0 0 / 0.05);
    --border-radius: 0.375rem;
    --transition: all 0.2s ease;
}

/* 基础样式 */
body {
    font-family: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    margin: 0;
    padding: 0;
    font-size: 18px;
    background-color: var(--background-color);
}

html {
    scroll-behavior: smooth;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 学术字体设置 */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Crimson Text', Georgia, serif;
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-primary);
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-light);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 65px;
}

.nav-logo a {
    text-decoration: none;
}

.nav-logo h2 {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.4rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2.5rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
    position: relative;
}

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

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

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

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
}

/* 主要内容区域 */
main {
    margin-top: 65px;
}

/* 英雄区域样式 */
.hero {
    padding: 4rem 0 5rem;
    background: linear-gradient(135deg, var(--background-light) 0%, var(--background-white) 100%);
}

.hero-content {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-text h1 {
    font-size: 3rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-text h2 {
    font-size: 1.3rem;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-weight: 400;
    font-family: 'Source Sans Pro', sans-serif;
}

.nowrap {
    white-space: nowrap;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

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

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.95rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background-color: #2c5282;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
}

.hero-image {
    display: flex;
    justify-content: center;
}

.profile-img {
    width: 280px;
    height: 280px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: var(--shadow-lg);
    border: 3px solid white;
}

/* 章节标题样式 */
.section-title {
    font-size: 2.25rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background-color: var(--primary-color);
    border-radius: 2px;
}

/* 关于我部分 */
.about {
    padding: 5rem 0;
    background-color: var(--background-white);
}

.about-text {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-text p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
    text-align: left;
}

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

.about-text a {
    color: var(--accent-color);
    text-decoration: none;
    border-bottom: 1px solid currentColor;
}

.rq {
    text-align: left;
    margin-bottom: 1.75rem;
    padding-left: 1.25rem;
    border-left: 2px solid var(--border-color);
}

.rq-title {
    font-family: 'Source Sans Pro', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.3rem;
}

.about-text .rq p {
    margin-bottom: 0.4rem;
}

.about-text .rq p.rq-papers {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-bottom: 0;
}

.about-text p.about-callout {
    color: var(--primary-color);
    font-weight: 600;
    padding-left: 1rem;
    border-left: 3px solid var(--primary-color);
}

/* News部分 */
.news {
    padding: 5rem 0;
    background-color: var(--background-light);
}

.news-list {
    max-width: 800px;
    margin: 0 auto;
    list-style: none;
}

.news-item {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 1.5rem;
    padding: 0.9rem 0;
    border-bottom: 1px solid var(--border-color);
}

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

.news-date {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 0.95rem;
    padding-top: 0.1rem;
}

.news-text {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.6;
}

.news-text strong {
    color: var(--text-primary);
}

.stat {
    text-align: center;
    padding: 1.5rem;
    background-color: var(--background-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.stat:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.stat h3 {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-family: 'Source Sans Pro', sans-serif;
}

.stat p {
    color: var(--text-secondary);
    font-weight: 500;
}

/* 研究兴趣部分 */
.research {
    padding: 5rem 0;
    background-color: var(--background-light);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.research-card {
    background-color: var(--background-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    text-align: center;
    border: 1px solid var(--border-light);
}

.research-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.research-icon {
    width: 70px;
    height: 70px;
    background-color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.research-icon i {
    font-size: 1.75rem;
    color: white;
}

.research-card h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.research-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 1.05rem;
}

/* Publications部分 */
.publications {
    padding: 5rem 0;
    background-color: var(--background-white);
}

.publications-content {
    max-width: 900px;
    margin: 0 auto;
}

.publication-item {
    background-color: var(--background-paper);
    padding: 2rem;
    margin-bottom: 2rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.publication-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.publication-item h4 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.authors {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.authors strong {
    color: var(--text-primary);
}

.venue {
    color: var(--accent-color);
    margin-bottom: 1rem;
    font-size: 0.95rem;
    font-weight: 500;
}

.pub-badge {
    display: inline-block;
    margin-left: 0.5rem;
    padding: 0.1rem 0.6rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    vertical-align: middle;
}

.badge-oral {
    background-color: #c05621;
    color: white;
}

.abstract {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

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

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: var(--background-light);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: var(--border-radius);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.pub-link:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-1px);
}

.view-all {
    text-align: center;
    margin-top: 2rem;
}

/* Ongoing Projects部分 */
.projects {
    padding: 5rem 0;
    background-color: var(--background-light);
}

.projects-content {
    max-width: 900px;
    margin: 0 auto;
}

.project-group-title {
    font-size: 1.35rem;
    color: var(--text-secondary);
    margin: 2.5rem 0 1.25rem;
}

.project-group-title:first-child {
    margin-top: 0;
}

.project-card {
    background-color: var(--background-white);
    padding: 1.75rem 2rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-light);
    border-left: 3px solid var(--border-color);
    border-radius: var(--border-radius);
}

.project-card h4 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.working-title {
    font-family: 'Source Sans Pro', sans-serif;
    font-size: 0.85rem;
    font-weight: 400;
    font-style: italic;
    color: var(--text-muted);
}

.project-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.project-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.collaborators {
    color: var(--text-muted);
    font-size: 0.95rem;
    font-style: italic;
}

.status-tag {
    background-color: var(--border-light);
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    white-space: nowrap;
}

/* 简历部分 */
.cv {
    padding: 5rem 0;
    background-color: var(--background-white);
}

.cv-content {
    max-width: 800px;
    margin: 0 auto;
}

.cv-download {
    text-align: center;
    margin-bottom: 3rem;
}

.cv-section {
    margin-bottom: 3rem;
}

.cv-section h3 {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.cv-item {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: var(--background-white);
    border-radius: var(--border-radius);
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.cv-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.cv-date {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 0.9rem;
}

.cv-details h4 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.cv-details p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

/* Blog部分 */
.blog {
    padding: 5rem 0;
    background-color: var(--background-light);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.blog-card {
    background-color: var(--background-paper);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.blog-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.blog-date {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.blog-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    line-height: 1.4;
}

.blog-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

.read-more {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.read-more:hover {
    color: #2c5282;
}

/* 联系方式部分 */
.contact {
    padding: 5rem 0;
    background-color: var(--background-white);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-info {
    display: grid;
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background-color: var(--background-white);
    border-radius: var(--border-radius);
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.contact-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.contact-item i {
    font-size: 1.4rem;
    color: var(--primary-color);
    width: 40px;
    text-align: center;
}

.contact-item h4 {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    font-size: 1rem;
}

.contact-item p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.95rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.social-link {
    width: 45px;
    height: 45px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: var(--transition);
}

.social-link:hover {
    background-color: #2c5282;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.social-link i {
    font-size: 1.1rem;
}

/* 页脚样式 */
.footer {
    background-color: var(--text-primary);
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 65px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-text h1 {
        font-size: 2.25rem;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .cv-item {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 200px;
        justify-content: center;
    }
    
    .publication-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .hero {
        padding: 3rem 0;
    }
    
    .section-title {
        font-size: 1.875rem;
    }
    
    .hero-text h1 {
        font-size: 2rem;
    }
    
    .profile-img {
        width: 220px;
        height: 220px;
    }
    
    .research-card,
    .blog-card,
    .project-card {
        padding: 1.5rem;
    }

    .news-item {
        grid-template-columns: 1fr;
        gap: 0.25rem;
    }
}