/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header and Navigation */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid #e5e7eb;
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1f2937;
}

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

.nav-menu a {
    text-decoration: none;
    color: #6b7280;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: #3b82f6;
}

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: 4rem 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.hero-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.hero-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    color: #3b82f6;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.1rem;
    color: #6b7280;
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-social {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.hero-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    width: 100%;
}

.btn-primary {
    background: #3b82f6;
    color: white;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: 0.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary:hover {
    background: #2563eb;
    transform: translateY(-2px);
}

.btn-secondary {
    background: white;
    color: #3b82f6;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: 0.5rem;
    font-weight: 500;
    border: 2px solid #3b82f6;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-secondary:hover {
    background: #3b82f6;
    color: white;
    transform: translateY(-2px);
}

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

.hero-image img {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    object-fit: cover;
    border: 8px solid white;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

/* Section Styles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1f2937;
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: #3b82f6;
    border-radius: 2px;
}

/* About Section */
.about {
    padding: 5rem 0;
    background: white;
}

.about-content {
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 1.1rem;
    color: #6b7280;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.about-content a {
    color: #3b82f6;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.about-content a:hover {
    color: #2563eb;
    text-decoration: underline;
}

.about-link {
    color: #1f2937 !important;
    text-decoration: none !important;
    font-weight: inherit;
}

.about-link:hover {
    color: #1f2937 !important;
    text-decoration: none !important;
}

/* Research Section */
.research {
    padding: 5rem 0;
    background: #f8fafc;
}

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

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.research-icon {
    width: 60px;
    height: 60px;
    background: #3b82f6;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 1.5rem;
}

.research-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1rem;
}

.research-card p {
    color: #6b7280;
    line-height: 1.6;
}

/* Publications Section */
.publications {
    padding: 5rem 0;
    background: white;
}

.full-paper-list {
    text-align: center;
    margin-bottom: 3rem;
}

.full-list-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: #3b82f6;
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
    padding: 0.75rem 1.5rem;
    border: 2px solid #3b82f6;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
}

.full-list-link:hover {
    background: #3b82f6;
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.publications-list {
    max-width: 1000px;
    margin: 0 auto;
}

.publication {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 2rem;
    padding: 1.2rem 0;
    border-bottom: 1px solid #e5e7eb;
}

.publication:last-child {
    border-bottom: none;
}

.publication-year {
    font-size: 1.1rem;
    font-weight: 600;
    color: #3b82f6;
}

.publication h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.3rem;
    line-height: 1.3;
}

.authors {
    color: #6b7280;
    margin-bottom: 0.2rem;
    line-height: 1.4;
}

.venue {
    color: #3b82f6;
    font-weight: 500;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.publication-link {
    color: #3b82f6;
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    transition: color 0.3s ease;
}

.publication-link:hover {
    color: #2563eb;
}

/* Experience Section */
.experience {
    padding: 5rem 0;
    background: #f8fafc;
}

.timeline {
    max-width: 1000px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 100px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #e5e7eb;
}

.timeline-item {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 190px;
    top: 0.5rem;
    width: 12px;
    height: 12px;
    background: #3b82f6;
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: 0 0 0 3px #e5e7eb;
}

.timeline-date {
    font-weight: 600;
    color: #3b82f6;
    text-align: right;
    padding-right: 1rem;
}

.timeline-content h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.2rem;
}

.timeline-content h4 {
    font-size: 1.1rem;
    font-weight: 500;
    color: #3b82f6;
    margin-bottom: 0.4rem;
}

.timeline-content p {
    color: #6b7280;
    line-height: 1.4;
}

/* Teaching Section */
.teaching {
    padding: 5rem 0;
    background: white;
}

/* Contact Section */
.contact {
    padding: 5rem 0;
    background: #f8fafc;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: #f8fafc;
    border-radius: 0.5rem;
    transition: background 0.3s ease;
}

.contact-item:hover {
    background: #e2e8f0;
}

.contact-item i {
    font-size: 1.3rem;
    color: #3b82f6;
    width: 20px;
}

.contact-item a {
    color: #1f2937;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.contact-item a:hover {
    color: #3b82f6;
}

/* Footer */
.footer {
    background: #1f2937;
    color: #9ca3af;
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }

    .hero {
        margin-top: 120px;
        padding: 2rem 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .hero-links {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
    }

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

    .hero-image img {
        width: 200px;
        height: 200px;
    }


    .research-areas {
        grid-template-columns: 1fr;
    }

    .publication {
        grid-template-columns: 1fr;
        gap: 1rem;
        text-align: center;
    }

    .timeline {
        padding-left: 0;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        grid-template-columns: 1fr;
        margin-left: 40px;
    }

    .timeline-item::before {
        left: -30px;
    }

    .timeline-date {
        text-align: left;
        padding-right: 0;
    }

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

    .container {
        padding: 0 1rem;
    }
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

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

.research-card,
.publication,
.timeline-item {
    animation: fadeInUp 0.6s ease forwards;
}