/* Reset & Variables */
:root {
    --primary: #308c84;
    --primary-light: #4ecdc4;
    --secondary: #2c3e50;
    --accent: #e6f2f1;
    --text-main: #334155;
    --text-muted: #64748b;
    --bg-main: #ffffff;
    --bg-light: #f5f7fa;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius: 12px;
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --max-width: 1200px;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-main);
    background-color: var(--bg-main);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: all 0.3s ease;
}

a:hover {
    color: var(--primary-light);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--secondary);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid transparent;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.navbar.scrolled {
    background-color: rgba(255, 255, 255, 0.9);
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    box-shadow: 0 4px 20px rgba(0,0,0,0.03);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1.2rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand {
    font-weight: 800;
    font-size: 1.35rem;
    background: linear-gradient(135deg, var(--secondary), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.03em;
}

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

.nav-links a {
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.95rem;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--primary);
    transition: width 0.3s ease;
    border-radius: 2px;
}

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

.hamburger {
    display: none;
    cursor: pointer;
    width: 24px;
    height: 18px;
    position: relative;
    z-index: 1001;
}

.hamburger span {
    display: block;
    position: absolute;
    height: 2px;
    width: 100%;
    background: var(--secondary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hamburger span:nth-child(1) { top: 0; }
.hamburger span:nth-child(2) { top: 8px; }
.hamburger span:nth-child(3) { top: 16px; }

/* Hero Section */
.hero {
    padding: 10rem 2rem 2rem;
    background: radial-gradient(circle at top left, #f1f5f9 0%, var(--bg-main) 100%);
    min-height: 40vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

/* Decorative background shapes */
.hero::before {
    content: '';
    position: absolute;
    top: -10%;
    right: -5%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.05) 0%, rgba(255,255,255,0) 70%);
    border-radius: 50%;
    z-index: 0;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6rem;
    position: relative;
    z-index: 1;
}

.hero-content {
    flex: 1;
    max-width: 650px;
    position: relative;
    left: 6rem;
    animation: fadeUp 1s ease-out;
}

.hero-indent {
    margin-left: 2rem;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.badge {
    display: inline-block;
    padding: 0.5rem 1.2rem;
    background: linear-gradient(135deg, #eff6ff, #dbeafe);
    color: var(--primary);
    border-radius: 30px;
    font-size: 0.875rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    box-shadow: 0 2px 10px rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.hero .name {
    font-family: 'Playfair Display', serif;
    font-size: 2.6rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--secondary);
    line-height: 1.1;
}

.hero .affiliation {
    font-size: 1.15rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 90%;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 3rem;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-main);
    font-weight: 600;
    transition: transform 0.2s ease;
}

.contact-link:hover {
    transform: translateX(5px);
    color: var(--primary);
}

.contact-link svg {
    color: var(--primary-light);
}

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.75rem;
    border-radius: 30px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), #1d4ed8);
    color: white;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
    transform: translateY(-2px);
    color: white;
}

.btn-outline {
    background-color: white;
    color: var(--secondary);
    border: 2px solid var(--border);
    box-shadow: var(--shadow-sm);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.15);
}

.hero-image-wrapper {
    position: relative;
    max-width: 320px;
    margin: 0 auto;
    left: -4rem;
    animation: fadeUp 1s ease-out 0.2s both;
}

.hero-image {
    width: 100%;
    height: auto;
    border-radius: 50%;
    box-shadow: var(--shadow-lg);
    position: relative;
    z-index: 2;
    aspect-ratio: 1/1;
    object-fit: cover;
    border: 6px solid white;
    transition: transform 0.5s ease;
}

.hero-image-wrapper:hover .hero-image {
    transform: scale(1.03) rotate(-2deg);
}

.hero-image-bg {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 105%;
    height: 105%;
    transform: translate(-45%, -45%);
    border-radius: 50%;
    background: conic-gradient(from 0deg, #d1fae5, #ecfdf5, #d1fae5);
    z-index: 1;
    animation: spin 10s linear infinite;
    opacity: 0.8;
}

@keyframes spin {
    100% { transform: translate(-45%, -45%) rotate(360deg); }
}

/* Generic Section Styles */
.section {
    padding: 6rem 2rem;
}

.section-light {
    background-color: var(--bg-light);
    border-top: 1px solid rgba(226, 232, 240, 0.5);
    border-bottom: 1px solid rgba(226, 232, 240, 0.5);
}

.section-container {
    max-width: 1000px;
    margin: 0 auto;
}

.section-header {
    margin-bottom: 4rem;
    text-align: center;
}

.section-title {
    font-size: 2.5rem;
    letter-spacing: -0.03em;
    margin-bottom: 0.5rem;
    font-weight: 800;
}

.section-subtitle {
    color: var(--text-muted);
    font-size: 1rem;
    font-weight: 500;
}

.section-line {
    width: 80px;
    height: 6px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    margin: 1.5rem auto 0;
    border-radius: 3px;
}

/* About Section */
.about-content {
    font-size: 1.15rem;
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
    line-height: 1.8;
}

/* News Section */
.news-timeline {
    position: relative;
    border-left: 3px solid #e2e8f0;
    margin-left: 1rem;
    padding-left: 2.5rem;
}

.news-item {
    position: relative;
    margin-bottom: 3rem;
    transition: transform 0.3s ease;
}

.news-item:hover {
    transform: translateX(5px);
}

.news-item::before {
    content: '';
    position: absolute;
    left: -48px;
    top: 4px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border: 4px solid white;
    box-shadow: 0 0 0 3px #e2e8f0, 0 0 10px rgba(37, 99, 235, 0.3);
    transition: all 0.3s ease;
}

.news-item:hover::before {
    box-shadow: 0 0 0 3px var(--primary-light), 0 0 15px rgba(37, 99, 235, 0.5);
    background: white;
}

.news-date {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--accent);
    border-radius: 20px;
}

.news-text {
    font-size: 1.1rem;
    color: var(--secondary);
    font-weight: 500;
}

/* Publications Section */
.subsection-title {
    font-size: 1.75rem;
    margin: 3.5rem 0 2rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border);
    font-weight: 700;
}

.pub-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.pub-card {
    background: white;
    border: 1px solid rgba(226, 232, 240, 0.8);
    border-radius: var(--radius);
    padding: 2rem;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.02);
}

.pub-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary), var(--primary-light));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.pub-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: transparent;
    transform: translateY(-4px);
}

.pub-card:hover::before {
    opacity: 1;
}

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

.pub-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.pub-title a {
    color: var(--secondary);
    background-image: linear-gradient(var(--primary), var(--primary));
    background-size: 0% 2px;
    background-repeat: no-repeat;
    background-position: left bottom;
    transition: background-size 0.3s ease;
}

.pub-title a:hover {
    color: var(--primary);
    background-size: 100% 2px;
}

.pub-venue {
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 500;
}

.pub-notes {
    margin-top: 1rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    background-color: var(--bg-light);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    display: inline-block;
}

/* Cards Grid (Teaching, Experience, Grants) */
.teaching-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2.5rem;
}

.teaching-card {
    background: white;
    border-radius: var(--radius);
    padding: 2.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(226, 232, 240, 0.8);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.teaching-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.3);
}

.teaching-card .uni-name {
    font-size: 1.35rem;
    color: var(--secondary);
    margin-bottom: 0.5rem;
    font-weight: 800;
}

.teaching-card .dept-name {
    font-size: 1rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.course-list {
    list-style: none;
}

.course-list li {
    padding: 1rem 0.5rem 1rem 2rem;
    border-bottom: 1px dashed var(--border);
    font-size: 1.05rem;
    color: var(--secondary);
    font-weight: 500;
    display: flex;
    align-items: flex-start;
    position: relative;
    transition: all 0.3s ease;
    border-radius: 8px;
}

.course-list li:hover {
    background-color: #f8fafc;
    transform: translateX(4px);
    border-bottom-color: transparent;
}

.course-list li::before {
    content: '';
    position: absolute;
    left: 0.5rem;
    top: 1.25rem;
    width: 14px;
    height: 14px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23308c84' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='9 18 15 12 9 6'%3E%3C/polyline%3E%3C/svg%3E");
    background-size: contain;
    background-repeat: no-repeat;
    transition: transform 0.3s ease;
}

.course-list li:hover::before {
    transform: translateX(3px);
}

.list-content {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.list-title {
    font-weight: 700;
    color: var(--secondary);
    line-height: 1.3;
}

.list-subtitle {
    font-size: 0.95rem;
    color: var(--text-muted);
    font-weight: 400;
    line-height: 1.5;
}

.course-list li:last-child {
    border-bottom: none;
}

.badge-date {
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: auto;
    background: var(--bg-light);
    padding: 0.3rem 0.75rem;
    border-radius: 20px;
    white-space: nowrap;
    border: 1px solid rgba(226, 232, 240, 0.8);
    box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}

#teaching .course-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    column-gap: 3rem;
    max-width: 800px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    #teaching .course-list {
        grid-template-columns: 1fr;
    }
}

/* Scroll Reveal Classes */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Footer */
.footer {
    background-color: var(--secondary);
    color: #94a3b8;
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), #3b82f6, #60a5fa);
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.visitor-count {
    font-size: 0.9rem;
    color: var(--secondary);
    background: transparent;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    user-select: none;
}

.back-to-top {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
    margin-top: 1rem;
    transition: all 0.3s ease;
}

.back-to-top:hover {
    background-color: var(--primary);
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

/* Responsive */
@media (max-width: 900px) {
    .hero-container {
        flex-direction: column;
        text-align: center;
        gap: 1.5rem;
    }
    
    .hero-content {
        left: 0;
    }
    
    .hero-image-wrapper {
        order: -1;
        left: 0;
    }

    .hero-indent {
        margin-left: 0;
    }
    
    .contact-info {
        align-items: center;
    }
    
    .social-links {
        justify-content: center;
    }
    
    .hero .name {
        font-size: 2.0rem;
    }
}

@media (max-width: 768px) {
    .hamburger {
        display: block;
    }
    
    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: 2rem;
        gap: 2rem;
        box-shadow: var(--shadow-lg);
        clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
        transition: clip-path 0.4s ease-in-out;
    }
    
    .nav-links.active {
        clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg);
        top: 8px;
    }
    
    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg);
        top: 8px;
    }

    .teaching-grid {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: 4rem 1.5rem;
    }
    
    .hero {
        padding: 7rem 1.5rem 2rem;
    }
}