:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: 6rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

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

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-affiliation {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.6s both;
}

.btn {
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

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

/* Sections */
.section {
    padding: 5rem 0;
}

.bg-light {
    background-color: var(--bg-light);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-primary);
}

.section-intro {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 800px;
    margin: 0 auto 3rem;
}

.content-box {
    background-color: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
}

.lead {
    font-size: 1.25rem;
    line-height: 1.8;
    color: var(--text-secondary);
    text-align: center;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--primary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    padding-left: 2rem;
}

.timeline-marker {
    position: absolute;
    left: -0.5rem;
    top: 0;
    width: 1rem;
    height: 1rem;
    border-radius: 50%;
    background-color: var(--primary-color);
    border: 3px solid white;
    box-shadow: var(--shadow-md);
}

.timeline-content {
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
}

.timeline-content h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.position {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.duration {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.location {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

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

/* Experience Cards */
.experience-card {
    background-color: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 2rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.experience-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

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

.card-header h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.institution {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.project {
    margin-top: 1.5rem;
}

.project h4 {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}

.project ul {
    padding-left: 1.5rem;
}

.project li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

/* Publications */
.publications-list {
    max-width: 900px;
    margin: 0 auto;
}

.publication-item {
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--border-color);
    transition: all 0.3s ease;
}

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

.publication-item.award-paper {
    border-left-color: var(--success-color);
}

.publication-item h4 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.publication-item h4 a {
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.publication-item h4 a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

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

.venue {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.badge {
    display: inline-block;
    background-color: var(--success-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.85rem;
    font-weight: 600;
    margin-top: 0.5rem;
}

.note {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-style: italic;
    margin-top: 0.5rem;
}

.note a {
    color: var(--primary-color);
    text-decoration: none;
}

.note a:hover {
    text-decoration: underline;
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.skill-category {
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
}

.skill-category h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    display: inline-block;
    background-color: var(--bg-light);
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 0.25rem;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.tag:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.mt-4 {
    margin-top: 2rem;
}

.teaching-list {
    padding-left: 1.5rem;
}

.teaching-list li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

/* Awards */
.awards-list {
    max-width: 800px;
    margin: 0 auto;
}

.award-item {
    display: flex;
    align-items: flex-start;
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
}

.award-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-md);
}

.award-icon {
    font-size: 2.5rem;
    margin-right: 1.5rem;
}

.award-content h4 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.award-content .description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.25rem;
}

.award-content .date {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-style: italic;
}

/* Contact */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.contact-card {
    background-color: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: all 0.3s ease;
}

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

.contact-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.contact-card h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.contact-card a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.contact-card a:hover {
    text-decoration: underline;
}

.contact-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.hobbies-section {
    background-color: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.hobbies-section h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.hobbies-section p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

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

.footer p {
    margin: 0.5rem 0;
    opacity: 0.8;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-md);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-links {
        flex-direction: column;
        gap: 0.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .timeline {
        padding-left: 1rem;
    }

    .timeline-item {
        padding-left: 1.5rem;
    }

    .card-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 4rem 0;
    }

    .hero-title {
        font-size: 2rem;
    }

    .section {
        padding: 3rem 0;
    }
}