/* CSS Custom Properties */
:root {
    --color-bg: #0a0a0b;
    --color-bg-secondary: #111113;
    --color-bg-tertiary: #1a1a1d;
    --color-surface: #18181b;
    --color-border: #27272a;
    --color-border-light: #3f3f46;
    --color-text: #fafafa;
    --color-text-secondary: #a1a1aa;
    --color-text-muted: #71717a;
    --color-primary: #3b82f6;
    --color-primary-light: #60a5fa;
    --color-primary-dark: #2563eb;
    --color-accent: #8b5cf6;
    --color-accent-light: #a78bfa;
    --color-success: #22c55e;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.3);
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

a {
    color: var(--color-primary-light);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 48px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    border-radius: 2px;
}

.section-intro {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    max-width: 700px;
    margin-bottom: 48px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 11, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-menu a {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition-fast);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 120px 24px 140px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(59, 130, 246, 0.15), transparent),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(139, 92, 246, 0.1), transparent);
    pointer-events: none;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-greeting {
    font-size: 1rem;
    color: var(--color-primary-light);
    font-weight: 500;
    margin-bottom: 12px;
    font-family: var(--font-mono);
}

.hero-name {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-title {
    font-size: 1.75rem;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: 32px;
}

.hero-cta {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: 8px;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    color: white;
    box-shadow: var(--shadow-md), 0 0 20px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(59, 130, 246, 0.4);
    color: white;
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-bg-tertiary);
    border-color: var(--color-border-light);
    color: var(--color-text);
}

.hero-visual {
    display: flex;
    flex-direction: column;
    gap: 24px;
    align-items: center;
}

.hero-image {
    position: relative;
    width: 280px;
    height: 280px;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid transparent;
    background: linear-gradient(var(--color-bg), var(--color-bg)) padding-box,
                linear-gradient(135deg, var(--color-primary), var(--color-accent)) border-box;
    box-shadow: 0 0 40px rgba(59, 130, 246, 0.2),
                0 0 80px rgba(139, 92, 246, 0.1);
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.hero-image:hover img {
    transform: scale(1.05);
}

.hero-cards {
    display: flex;
    flex-direction: column;
    gap: 16px;
    width: 100%;
}

.hero-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 20px 24px;
    display: flex;
    align-items: flex-start;
    gap: 16px;
    transition: all var(--transition-base);
    cursor: pointer;
    position: relative;
}

.hero-card:hover {
    border-color: var(--color-primary);
    transform: translateX(8px);
    box-shadow: var(--shadow-glow);
}

.hero-card.expanded {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
}

.card-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-top: 2px;
}

.card-icon svg {
    width: 24px;
    height: 24px;
    color: white;
}

.card-content {
    flex: 1;
    min-width: 0;
}

.card-title {
    font-weight: 500;
    color: var(--color-text-secondary);
    display: block;
    transition: color var(--transition-fast);
}

.hero-card:hover .card-title,
.hero-card.expanded .card-title {
    color: var(--color-text);
}

.card-summary {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin-top: 0;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height var(--transition-slow), opacity var(--transition-base), margin-top var(--transition-base);
}

.hero-card.expanded .card-summary {
    max-height: 200px;
    opacity: 1;
    margin-top: 12px;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    color: var(--color-text-muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    z-index: 2;
}

.scroll-indicator {
    width: 24px;
    height: 40px;
    border: 2px solid var(--color-border);
    border-radius: 12px;
    position: relative;
}

.scroll-indicator::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--color-primary);
    border-radius: 2px;
    animation: scroll 2s ease-in-out infinite;
}

@keyframes scroll {
    0%, 100% { top: 8px; opacity: 1; }
    50% { top: 20px; opacity: 0.5; }
}

/* About Section */
.about {
    background: var(--color-bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
}

.about-text .lead {
    font-size: 1.25rem;
    color: var(--color-text);
    margin-bottom: 24px;
    font-weight: 400;
}

.about-text p {
    color: var(--color-text-secondary);
    margin-bottom: 20px;
}

.about-highlights {
    display: flex;
    gap: 40px;
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid var(--color-border);
}

.highlight {
    display: flex;
    flex-direction: column;
}

.highlight-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.highlight-label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-top: 4px;
}

.about-education h3 {
    font-size: 1.25rem;
    margin-bottom: 24px;
    color: var(--color-text);
}

.education-item {
    padding: 16px 0;
    border-bottom: 1px solid var(--color-border);
}

.education-item:last-child {
    border-bottom: none;
}

.edu-degree {
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 4px;
}

.edu-school {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.edu-note {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    font-style: italic;
}

/* Timeline / Experience */
.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--color-primary), var(--color-accent), var(--color-border));
}

.timeline-item {
    position: relative;
    padding-bottom: 48px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: -40px;
    top: 6px;
    width: 16px;
    height: 16px;
    background: var(--color-bg);
    border: 3px solid var(--color-primary);
    border-radius: 50%;
    z-index: 1;
}

.timeline-item:hover .timeline-marker {
    background: var(--color-primary);
    box-shadow: 0 0 12px var(--color-primary);
}

.timeline-content {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 24px;
    transition: all var(--transition-base);
}

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

.timeline-header h3 {
    font-size: 1.25rem;
    margin-bottom: 4px;
}

.timeline-company {
    display: block;
    color: var(--color-primary-light);
    font-weight: 500;
    margin-bottom: 4px;
}

.timeline-date {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
    margin-bottom: 16px;
}

/* Timeline Layout - Two Column */
.timeline-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.timeline-layout:has(.timeline-media) {
    grid-template-columns: 1fr 280px;
}

.timeline-body p {
    color: var(--color-text-secondary);
    margin-bottom: 12px;
}

.timeline-body ul {
    list-style: none;
    padding: 0;
}

.timeline-body li {
    position: relative;
    padding-left: 20px;
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    margin-bottom: 8px;
}

.timeline-body > ul > li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    background: var(--color-primary);
    border-radius: 50%;
}

/* Timeline Media/Presentations - Right Column */
.timeline-media {
    padding-left: 20px;
    border-left: 1px solid var(--color-border);
}

.timeline-media h4 {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

.media-list {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.media-list li {
    padding-left: 0;
    margin-bottom: 0;
}

.media-list li::before {
    display: none;
}

.media-list a {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 12px;
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    color: var(--color-text-secondary);
    font-size: 0.8125rem;
    line-height: 1.4;
    transition: all var(--transition-fast);
}

.media-list a:hover {
    background: var(--color-bg-secondary);
    border-color: var(--color-primary);
    color: var(--color-primary-light);
}

.media-list svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    opacity: 0.7;
    margin-top: 1px;
}

.media-list a:hover svg {
    opacity: 1;
}

/* Research Section */
.research {
    background: var(--color-bg-secondary);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.research-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 28px;
    transition: all var(--transition-base);
}

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

.research-funding {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-success);
    margin-bottom: 12px;
    font-family: var(--font-mono);
}

.research-card h3 {
    font-size: 1rem;
    margin-bottom: 12px;
    line-height: 1.4;
}

.research-agency {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.research-years {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
    margin-bottom: 12px;
}

.research-role {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(139, 92, 246, 0.15);
    color: var(--color-accent-light);
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 100px;
}

/* Publications */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.publication {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 24px;
    transition: all var(--transition-base);
}

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

.publication h3 {
    font-size: 1.0625rem;
    margin-bottom: 8px;
    line-height: 1.4;
}

.pub-authors {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.pub-venue {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    font-style: italic;
}

/* Projects */
.projects {
    background: var(--color-bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.project-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 28px;
    display: flex;
    flex-direction: column;
    transition: all var(--transition-base);
    color: var(--color-text);
}

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

.project-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.project-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.project-card h3 {
    font-size: 1.25rem;
    margin-bottom: 8px;
}

.project-card p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    margin-bottom: 16px;
    flex-grow: 1;
}

.project-sponsor {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Expertise */
.expertise-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.expertise-category {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 28px;
}

.expertise-category h3 {
    font-size: 1rem;
    margin-bottom: 20px;
    color: var(--color-primary-light);
}

.expertise-category ul {
    list-style: none;
}

.expertise-category li {
    padding: 8px 0;
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    border-bottom: 1px solid var(--color-border);
}

.expertise-category li:last-child {
    border-bottom: none;
}

/* Contact */
.contact {
    background: var(--color-bg-secondary);
    text-align: center;
}

.contact .section-title::after {
    left: 50%;
    transform: translateX(-50%);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
}

.contact-intro {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin-bottom: 40px;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 24px;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 32px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    color: var(--color-text);
    font-weight: 500;
    transition: all var(--transition-base);
}

.contact-link:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    color: var(--color-text);
}

.contact-link svg {
    width: 24px;
    height: 24px;
}

/* Footer */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-visual {
        max-width: 400px;
        margin: 0 auto;
    }

    .hero-image {
        width: 220px;
        height: 220px;
    }

    .hero-cta {
        justify-content: center;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .timeline-layout,
    .timeline-layout:has(.timeline-media) {
        grid-template-columns: 1fr;
    }

    .timeline-media {
        padding-left: 0;
        padding-top: 16px;
        margin-top: 16px;
        border-left: none;
        border-top: 1px solid var(--color-border);
    }

    .research-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .expertise-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-bottom: 1px solid var(--color-border);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all var(--transition-base);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }

    .nav-toggle {
        display: flex;
    }

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

    .hero-title {
        font-size: 1.25rem;
    }

    .hero-image {
        width: 180px;
        height: 180px;
    }

    .section {
        padding: 60px 0;
    }

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

    .about-highlights {
        flex-direction: column;
        gap: 24px;
    }

    .timeline {
        padding-left: 24px;
    }

    .timeline-marker {
        left: -24px;
        width: 12px;
        height: 12px;
    }

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

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

    .contact-links {
        flex-direction: column;
        align-items: center;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 100px 16px 40px;
    }

    .container {
        padding: 0 16px;
    }

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

    .btn {
        width: 100%;
    }

    .hero-cta {
        flex-direction: column;
    }
}