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

:root {
    --color-bg: #0a0a0f;
    --color-bg-alt: #111118;
    --color-surface: #1a1a24;
    --color-border: #2a2a3a;
    --color-text: #e4e4ed;
    --color-text-muted: #9494a8;
    --color-accent: #6c63ff;
    --color-accent-light: #8b83ff;
    --color-accent-glow: rgba(108, 99, 255, 0.15);
    --color-highlight: #00d4aa;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --max-width: 1100px;
    --nav-height: 64px;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: var(--font-body);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-accent-light);
    text-decoration: none;
    transition: color 0.2s;
}

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

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navbar ===== */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    z-index: 1000;
    transition: border-color 0.3s;
}

#navbar.scrolled {
    border-bottom-color: var(--color-border);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-text);
    letter-spacing: -0.5px;
}

.nav-logo:hover {
    color: var(--color-accent-light);
}

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

.nav-links a {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.025em;
    transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
}

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

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s;
}

/* ===== Hero ===== */
#hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--nav-height) + 40px) 24px 40px;
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: var(--max-width);
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-greeting {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--color-accent-light);
    margin-bottom: 12px;
    letter-spacing: 0.05em;
}

.hero-text h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-accent-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-tagline {
    font-size: 1.2rem;
    color: var(--color-text-muted);
    margin-bottom: 8px;
}

.hero-tagline .accent {
    color: var(--color-accent);
}

.hero-sub {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    margin-bottom: 32px;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.25s;
    cursor: pointer;
    border: none;
    font-family: var(--font-body);
}

.btn-primary {
    background: var(--color-accent);
    color: #fff;
}

.btn-primary:hover {
    background: var(--color-accent-light);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 8px 24px rgba(108, 99, 255, 0.3);
}

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

.btn-outline:hover {
    border-color: var(--color-accent);
    color: var(--color-accent-light);
    transform: translateY(-1px);
}

/* Hero Photo */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-photo {
    width: 300px;
    height: 380px;
    border-radius: 16px;
    overflow: hidden;
    border: 2px solid var(--color-border);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4), 0 0 40px var(--color-accent-glow);
    position: relative;
}

.hero-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center top;
    display: block;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.scroll-indicator span {
    font-size: 0.7rem;
    font-family: var(--font-mono);
    color: var(--color-text-muted);
    letter-spacing: 0.15em;
    text-transform: uppercase;
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, var(--color-accent), transparent);
    animation: scroll-pulse 2s ease-in-out infinite;
}

@keyframes scroll-pulse {
    0%, 100% { opacity: 1; transform: scaleY(1); }
    50% { opacity: 0.3; transform: scaleY(0.5); }
}

/* ===== Sections ===== */
section {
    padding: 100px 0;
}

section:nth-child(even) {
    background: var(--color-bg-alt);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    display: block;
    width: 48px;
    height: 3px;
    background: var(--color-accent);
    margin-top: 12px;
    border-radius: 2px;
}

.section-intro {
    font-size: 1.05rem;
    color: var(--color-text-muted);
    max-width: 680px;
    margin-bottom: 48px;
    line-height: 1.8;
}

/* ===== About ===== */
.about-layout {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 48px;
    align-items: start;
}

.about-left {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.about-photo {
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--color-border);
}

.about-photo img {
    width: 100%;
    height: auto;
    display: block;
}

.about-right p {
    margin-bottom: 16px;
    color: var(--color-text-muted);
    line-height: 1.8;
}

.about-right strong {
    color: var(--color-text);
    font-weight: 600;
}

.about-text p {
    margin-bottom: 16px;
    color: var(--color-text-muted);
    line-height: 1.8;
}

.about-text strong {
    color: var(--color-text);
    font-weight: 600;
}

.about-quote {
    margin: 20px 0;
    padding: 16px 24px;
    border-left: 3px solid var(--color-accent);
    background: var(--color-accent-glow);
    border-radius: 0 8px 8px 0;
    font-style: italic;
    color: var(--color-text);
    font-size: 0.95rem;
    line-height: 1.7;
}

.about-quote cite {
    display: block;
    margin-top: 8px;
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-style: normal;
    font-family: var(--font-mono);
}

.detail-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
}

.detail-card h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--color-accent-light);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.education-list, .cert-list {
    list-style: none;
}

.education-list li {
    margin-bottom: 14px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--color-border);
}

.education-list li:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.degree {
    display: block;
    font-weight: 600;
    color: var(--color-text);
    font-size: 0.95rem;
}

.school {
    display: block;
    color: var(--color-text-muted);
    font-size: 0.85rem;
}

.year {
    display: block;
    color: var(--color-text-muted);
    font-size: 0.8rem;
    font-family: var(--font-mono);
}

.cert-list li {
    padding: 8px 0;
    color: var(--color-text-muted);
    font-size: 0.9rem;
    border-bottom: 1px solid var(--color-border);
}

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

/* ===== Research ===== */
.research-areas {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 48px;
}

.research-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 32px;
    transition: border-color 0.3s, transform 0.3s;
}

.research-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-2px);
}

.research-icon {
    width: 40px;
    height: 40px;
    margin-bottom: 16px;
    color: var(--color-accent-light);
}

.research-icon svg {
    width: 100%;
    height: 100%;
}

.research-card h3 {
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--color-text);
}

.research-card p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

.lab-callout {
    background: var(--color-accent-glow);
    border: 1px solid rgba(108, 99, 255, 0.3);
    border-radius: 12px;
    padding: 36px;
}

.lab-callout h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.lab-callout p {
    color: var(--color-text-muted);
    margin-bottom: 20px;
    line-height: 1.8;
}

/* ===== Dissertation ===== */
.dissertation-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 40px;
    position: relative;
    overflow: hidden;
}

.dissertation-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-accent), var(--color-highlight));
}

.dissertation-status {
    margin-bottom: 16px;
}

.status-badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-family: var(--font-mono);
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    background: rgba(0, 212, 170, 0.1);
    color: var(--color-highlight);
    border: 1px solid rgba(0, 212, 170, 0.3);
}

.dissertation-title {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--color-text);
}

.dissertation-description {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    line-height: 1.8;
    max-width: 720px;
    margin-bottom: 20px;
}

.dissertation-advisors {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

.dissertation-advisors span {
    color: var(--color-accent-light);
}

/* ===== Publications ===== */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-bottom: 36px;
}

.pub-card {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 24px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 32px;
    transition: border-color 0.3s;
}

.pub-card:hover {
    border-color: var(--color-accent);
}

.pub-year {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-accent-light);
    padding-top: 4px;
}

.pub-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
    line-height: 1.4;
}

.pub-title a {
    color: var(--color-text);
    transition: color 0.2s;
}

.pub-title a:hover {
    color: var(--color-accent-light);
}

.pub-authors {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 6px;
}

.pub-venue {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: 12px;
}

.venue-name {
    font-style: italic;
    color: var(--color-highlight);
}

.pub-description {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    line-height: 1.7;
}

.pub-actions {
    display: flex;
    gap: 12px;
    margin-top: 16px;
}

.pub-link,
.pub-download {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    transition: all 0.2s;
}

.pub-link {
    background: var(--color-accent-glow);
    color: var(--color-accent-light);
    border: 1px solid rgba(108, 99, 255, 0.3);
}

.pub-link:hover {
    background: var(--color-accent);
    color: #fff;
}

.pub-download {
    background: transparent;
    color: var(--color-text-muted);
    border: 1px solid var(--color-border);
}

.pub-download:hover {
    border-color: var(--color-highlight);
    color: var(--color-highlight);
}

.pub-download svg {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
    display: inline-block;
    vertical-align: middle;
}

.pub-download svg * {
    vector-effect: non-scaling-stroke;
}

.scholar-link {
    text-align: center;
}

/* ===== Experience Timeline ===== */
.timeline {
    position: relative;
    padding-left: 32px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 8px;
    bottom: 8px;
    width: 1px;
    background: var(--color-border);
}

.timeline-item {
    position: relative;
    padding-bottom: 36px;
}

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

.timeline-marker {
    position: absolute;
    left: -32px;
    top: 8px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: var(--color-bg);
    border: 2px solid var(--color-accent);
    z-index: 1;
}

.timeline-item:first-child .timeline-marker {
    background: var(--color-accent);
    box-shadow: 0 0 12px rgba(108, 99, 255, 0.4);
}

.timeline-date {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--color-accent-light);
    display: block;
    margin-bottom: 4px;
}

.timeline-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.timeline-company {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 8px;
}

.timeline-content p:last-child {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* ===== Contact ===== */
#contact {
    text-align: center;
}

#contact .section-title {
    display: block;
}

#contact .section-title::after {
    margin: 12px auto 0;
}

#contact .section-intro {
    margin-left: auto;
    margin-right: auto;
}

.contact-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px;
}

.contact-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 28px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    color: var(--color-text);
    font-size: 0.9rem;
    transition: border-color 0.3s, transform 0.3s;
}

.contact-card:hover {
    border-color: var(--color-accent);
    color: var(--color-text);
    transform: translateY(-2px);
}

.contact-card svg {
    width: 20px;
    height: 20px;
    color: var(--color-accent-light);
    flex-shrink: 0;
}

/* ===== Footer ===== */
footer {
    padding: 24px 0;
    text-align: center;
    border-top: 1px solid var(--color-border);
}

footer p {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

/* ===== Fade-in Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

    .hero-visual {
        display: none;
    }

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

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

    .pub-card {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-bottom: 1px solid var(--color-border);
        flex-direction: column;
        padding: 20px 24px;
        gap: 16px;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .scroll-indicator {
        display: none;
    }

    section {
        padding: 64px 0;
    }

    .section-title {
        font-size: 1.6rem;
    }
}

@media (max-width: 480px) {
    .contact-links {
        flex-direction: column;
        align-items: center;
    }

    .contact-card {
        width: 100%;
        justify-content: center;
    }
}