/* 全局样式和变量 */
:root {
    --primary-color: #1d1d1f;
    --secondary-color: #0066cc;
    --accent-color: #f5f5f7;
    --text-color: #1d1d1f;
    --text-light: #86868b;
    --white: #ffffff;
    --section-spacing: 80px;
    --card-radius: 18px;
    --transition-speed: 0.3s;
    --shadow-light: 0 5px 15px rgba(0, 0, 0, 0.05);
    --shadow-medium: 0 10px 30px rgba(0, 0, 0, 0.08);
    --shadow-heavy: 0 20px 40px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--white);
    overflow-x: hidden;
}

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

/* 动画关键帧 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* 导航栏 */
header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    padding: 15px 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    transition: all var(--transition-speed);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.logo span {
    color: var(--secondary-color);
}

nav ul {
    display: flex;
    list-style: none;
}

nav li {
    margin-left: 30px;
}

nav a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 14px;
    font-weight: 400;
    transition: color var(--transition-speed);
    position: relative;
}

nav a:hover {
    color: var(--secondary-color);
}

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

nav a:hover::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--primary-color);
    cursor: pointer;
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background-color: var(--white);
    box-shadow: var(--shadow-heavy);
    z-index: 999;
    padding: 20px;
    animation: fadeIn 0.3s ease-out;
}

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

.mobile-menu ul {
    list-style: none;
}

.mobile-menu li {
    margin-bottom: 20px;
}

.mobile-menu a {
    text-decoration: none;
    color: var(--primary-color);
    font-size: 18px;
    font-weight: 500;
    display: block;
    padding: 10px 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

/* 英雄区域 */
.hero {
    padding-top: 120px;
    padding-bottom: 80px;
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
    min-height: 90vh;
    display: flex;
    align-items: center;
}

.profile-img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid var(--white);
    box-shadow: var(--shadow-heavy);
    margin-bottom: 30px;
    animation: fadeInUp 0.8s ease-out;
}

.img-fallback {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background-color: #f0f0f0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    font-weight: 600;
    font-size: 18px;
    margin: 0 auto 30px;
    border: 5px solid var(--white);
    box-shadow: var(--shadow-heavy);
}

.hero h1 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.5px;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero h2 {
    font-size: 24px;
    font-weight: 400;
    color: var(--text-light);
    margin-bottom: 30px;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero p {
    max-width: 700px;
    margin: 0 auto 40px;
    font-size: 18px;
    line-height: 1.8;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

.contact-info {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-top: 30px;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.8s both;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 10px;
    background-color: var(--white);
    padding: 12px 20px;
    border-radius: 50px;
    box-shadow: var(--shadow-light);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

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

.contact-item i {
    color: var(--secondary-color);
    font-size: 18px;
}

.copy-btn {
    background: none;
    border: none;
    color: var(--secondary-color);
    cursor: pointer;
    padding: 5px;
    border-radius: 4px;
    transition: background-color var(--transition-speed);
}

.copy-btn:hover {
    background-color: rgba(0, 102, 204, 0.1);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 40px;
    animation: fadeInUp 0.8s ease-out 1s both;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background-color: var(--white);
    border-radius: 50%;
    color: var(--primary-color);
    font-size: 20px;
    text-decoration: none;
    box-shadow: var(--shadow-light);
    transition: all var(--transition-speed);
}

.social-link:hover {
    background-color: var(--secondary-color);
    color: var(--white);
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

/* 内容区域 */
section {
    padding: var(--section-spacing) 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

section:last-child {
    border-bottom: none;
}

.section-alt {
    background-color: var(--accent-color);
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
    letter-spacing: -0.5px;
}

/* 研究方向 */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.research-card {
    background-color: var(--white);
    border-radius: var(--card-radius);
    padding: 40px 30px;
    text-align: center;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.research-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-heavy);
}

.research-icon {
    font-size: 40px;
    color: var(--secondary-color);
    margin-bottom: 20px;
}

.research-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    font-weight: 600;
}

.research-card p {
    color: var(--text-light);
    font-size: 16px;
    line-height: 1.7;
}

/* 个人爱好 */
.hobby-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.hobby-item {
    text-align: center;
    padding: 30px 20px;
    border-radius: var(--card-radius);
    background-color: var(--white);
    box-shadow: var(--shadow-light);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.hobby-item:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-medium);
}

.hobby-icon {
    font-size: 36px;
    color: var(--secondary-color);
    margin-bottom: 20px;
}

.hobby-item h3 {
    font-size: 22px;
    margin-bottom: 15px;
    font-weight: 600;
}

.hobby-item p {
    color: var(--text-light);
    line-height: 1.7;
}

/* 生活分享 */
.life-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.life-card {
    border-radius: var(--card-radius);
    overflow: hidden;
    background-color: var(--white);
    box-shadow: var(--shadow-medium);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.life-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-heavy);
}

.life-image {
    height: 200px;
    width: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

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

.life-content {
    padding: 30px;
}

.life-date {
    color: var(--text-light);
    font-size: 14px;
    margin-bottom: 10px;
    display: block;
}

.life-content h3 {
    font-size: 20px;
    margin-bottom: 15px;
    font-weight: 600;
}

.life-content p {
    color: var(--text-light);
    line-height: 1.7;
}

/* 页脚 */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section {
    flex: 1;
    min-width: 250px;
}

.footer-section h3 {
    font-size: 20px;
    margin-bottom: 20px;
    font-weight: 600;
}

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

.footer-links li {
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.footer-links a {
    color: #a1a1a6;
    text-decoration: none;
    transition: color var(--transition-speed);
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.footer-links i {
    width: 20px;
    text-align: center;
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #86868b;
    font-size: 14px;
    line-height: 1.6;
}

/* 动画类 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s, transform 0.6s;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero h1 {
        font-size: 40px;
    }
    
    .hero h2 {
        font-size: 22px;
    }
    
    .section-title {
        font-size: 36px;
    }
    
    .research-grid {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    }
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 36px;
    }
    
    .hero h2 {
        font-size: 20px;
    }
    
    .hero p {
        font-size: 16px;
    }
    
    .section-title {
        font-size: 32px;
        margin-bottom: 40px;
    }
    
    nav ul {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .contact-info {
        flex-direction: column;
        align-items: center;
        gap: 15px;
    }
    
    .contact-item {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 30px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding-top: 100px;
        padding-bottom: 60px;
    }
    
    .hero h1 {
        font-size: 30px;
    }
    
    .hero h2 {
        font-size: 18px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .research-card, .hobby-item, .life-card {
        padding: 25px 20px;
    }
    
    .profile-img, .img-fallback {
        width: 180px;
        height: 180px;
    }
}

/* 工具提示 */
.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip .tooltip-text {
    visibility: hidden;
    width: 120px;
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    border-radius: 6px;
    padding: 5px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity var(--transition-speed);
    font-size: 12px;
}

.tooltip:hover .tooltip-text {
    visibility: visible;
    opacity: 1;
}