:root {
    --primary-color: #660874;
    /* Tsinghua Purple */
    --secondary-color: #4a0652;
    --text-color: #333;
    --light-text: #666;
    --bg-color: #ffffff;
    --section-bg: #f9f9f9;
    --accent-color: #ef4444;
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

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

body {
    font-family: var(--font-main);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

/* Header & Navigation */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

nav {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
    font-size: 0.95rem;
}

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

/* Main Content Layout */
main {
    max-width: 1000px;
    margin: 6rem auto 4rem;
    padding: 0 2rem;
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    gap: 4rem;
    margin-bottom: 4rem;
}

.hero-content {
    flex: 1;
}

.hero-image {
    width: 280px;
    height: 420px;
    border-radius: 24px;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    letter-spacing: -1px;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.bio {
    font-size: 1.1rem;
    color: var(--light-text);
    margin-bottom: 2rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--light-text);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid #eee;
    transition: all 0.3s;
}

.social-link:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Sections */
section {
    padding: 4rem 0;
    border-top: 1px solid #eee;
}

section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

/* Publications */
.publication-item {
    margin-bottom: 2rem;
    padding-left: 1rem;
    border-left: 3px solid #eee;
    transition: border-color 0.3s;
}

.publication-item:hover {
    border-left-color: var(--primary-color);
}

.pub-title {
    font-weight: 700;
    font-size: 1.15rem;
    display: block;
    margin-bottom: 0.25rem;
}

.pub-authors {
    color: var(--light-text);
    font-size: 0.95rem;
    margin-bottom: 0.25rem;
}

.pub-venue {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--primary-color);
}

.pub-tag {
    display: inline-block;
    padding: 2px 8px;
    background: #f0f0f0;
    border-radius: 4px;
    font-size: 0.8rem;
    margin-right: 0.5rem;
}

/* News */
.news-item {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.news-date {
    min-width: 100px;
    font-weight: 600;
    color: var(--primary-color);
}

/* Footer */
footer {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--light-text);
    background: var(--section-bg);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeInUp 0.8s forwards;
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        flex-direction: column-reverse;
        text-align: center;
        gap: 2rem;
    }

    .nav-links {
        display: none;
    }

    .social-links {
        justify-content: center;
    }
}