/* ========================================
   Style: Glassmorphism / Modern Glass
   Design Philosophy: Translucent layers,
   blur effects, depth, modern elegance
   ======================================== */

:root {
    /* Light Theme - Soft Glass */
    --bg-primary: #e8eef5;
    --bg-secondary: rgba(255, 255, 255, 0.6);
    --bg-tertiary: rgba(255, 255, 255, 0.4);
    --bg-card: rgba(255, 255, 255, 0.7);

    --text-primary: #1a1f36;
    --text-secondary: #4a5568;
    --text-muted: #718096;

    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-tertiary: #ec4899;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);

    --border-color: rgba(255, 255, 255, 0.5);
    --border-hover: rgba(255, 255, 255, 0.8);

    --shadow-sm: 0 2px 10px rgba(99, 102, 241, 0.1);
    --shadow-md: 0 8px 32px rgba(99, 102, 241, 0.15);
    --shadow-lg: 0 16px 48px rgba(99, 102, 241, 0.2);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.3);

    /* Glass Effect */
    --glass-blur: blur(20px);
    --glass-bg: rgba(255, 255, 255, 0.25);
    --glass-border: 1px solid rgba(255, 255, 255, 0.3);

    /* Typography */
    --font-display: 'Source Sans 3', 'Helvetica Neue', sans-serif;
    --font-body: 'Source Sans 3', 'Helvetica Neue', sans-serif;
    --font-mono: 'IBM Plex Mono', monospace;
    --font-sans: 'Source Sans 3', sans-serif;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 5rem;

    --transition-fast: 200ms ease;
    --transition-base: 400ms cubic-bezier(0.4, 0, 0.2, 1);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --radius-full: 9999px;
}

/* ---- Global Resets ---- */
* { -webkit-tap-highlight-color: transparent; }
[data-theme="dark"] { color-scheme: dark; }
[data-theme="light"] { color-scheme: light; }
::selection { background: var(--accent-primary); color: #fff; }

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #0f0f1a;
    --bg-secondary: rgba(30, 30, 50, 0.6);
    --bg-tertiary: rgba(40, 40, 70, 0.4);
    --bg-card: rgba(30, 30, 50, 0.7);

    --text-primary: #f0f0ff;
    --text-secondary: #a0a0c0;
    --text-muted: #6a6a8a;

    --border-color: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(255, 255, 255, 0.2);

    --glass-bg: rgba(30, 30, 50, 0.4);
    --glass-border: 1px solid rgba(255, 255, 255, 0.1);
}

/* ========================================
   Reset & Base
   ======================================== */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 100px;
}

body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    background-image:
        radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(236, 72, 153, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(139, 92, 246, 0.1) 0%, transparent 60%);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 16px;
    min-height: 100vh;
    transition: background-color var(--transition-base), color var(--transition-base);
}

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

a:hover {
    color: var(--accent-secondary);
}

/* ========================================
   Navigation - Floating Glass Bar
   ======================================== */

.navbar {
    position: fixed;
    top: var(--space-md);
    left: var(--space-xl);
    right: var(--space-xl);
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.nav-container {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-xl);
    max-width: 1200px;
    margin: 0 auto;
}

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 600;
    white-space: nowrap;
    flex-shrink: 0;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-logo:hover { text-decoration: none; }

.logo-bracket {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-text { color: var(--text-primary); }

.nav-links {
    display: flex;
    gap: var(--space-sm);
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.nav-links a:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.mobile-menu-toggle { display: none; }

.nav-controls {
    display: flex;
    align-items: center;
    background: var(--bg-tertiary);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-full);
    padding: 4px;
    border: var(--glass-border);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: transparent;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.nav-btn:hover {
    color: var(--accent-primary);
    background: var(--bg-card);
}

.nav-btn-icon { width: 16px; height: 16px; flex-shrink: 0; }
.nav-btn-label { white-space: nowrap; }

.sun-icon { display: block; }
.moon-icon { display: none; }
[data-theme="dark"] .sun-icon { display: none; }
[data-theme="dark"] .moon-icon { display: block; }
[data-theme="dark"] .theme-label::after { content: "Light"; }
[data-theme="light"] .theme-label::after { content: "Dark"; }
.theme-label { font-size: 0; }
.theme-label::after { font-size: 0.85rem; }

/* ========================================
   Hero - Layered Glass Layout
   ======================================== */

.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 100px var(--space-xl) var(--space-2xl);
    position: relative;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
    overflow: hidden;
}

.grid-overlay { display: none; }

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.5;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 500px; height: 500px;
    background: var(--accent-primary);
    top: -150px; right: -100px;
}

.orb-2 {
    width: 400px; height: 400px;
    background: var(--accent-tertiary);
    bottom: -100px; left: -100px;
    animation-delay: -10s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, -30px) scale(1.05); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: var(--space-3xl);
    align-items: center;
    width: 100%;
}

.hero-greeting {
    font-size: 0.95rem;
    color: var(--accent-primary);
    margin-bottom: var(--space-sm);
    font-weight: 600;
}

.hero-name {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: var(--space-md);
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-title {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
    font-weight: 500;
}

.hero-description {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-xl);
}

.hero-description p {
    margin-bottom: var(--space-md);
}

.hero-description p:last-child {
    margin-bottom: 0;
}

.hero-description a {
    color: var(--accent-primary);
    text-decoration: none;
    font-weight: inherit;
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-fast);
}
.hero-description a:hover {
    border-bottom-color: var(--accent-primary);
}

.highlight {
    color: var(--accent-primary);
    font-weight: 600;
}

.hero-stats-box {
    display: inline-flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-lg) var(--space-xl);
    margin-bottom: var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-lg);
}

.hero-stats-divider {
    width: 1px;
    align-self: stretch;
    background: var(--border-color);
}

.hero-stats-box .hero-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    justify-content: center;
}

@media (max-width: 600px) {
    .hero-stats-box {
        flex-direction: column;
    }
    .hero-stats-divider {
        width: 100%;
        height: 1px;
    }
}

.hero-stats {
    display: flex;
    gap: var(--space-xl);
}

.stat { display: flex; flex-direction: column; align-items: center; white-space: nowrap; }

.stat-number {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Hero Links (scholar, github, etc.) */
.hero-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.hero-link-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: var(--glass-border);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.hero-link-item:hover {
    color: var(--accent-primary);
    background: var(--bg-card);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.hero-link-item svg {
    width: 16px;
    height: 16px;
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
}

.btn {
    padding: var(--space-md) var(--space-xl);
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
    cursor: pointer;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    border: none;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
    background-size: 200% 200%;
    animation: gradientRotate 3s ease infinite;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
    color: white;
}

.btn-secondary {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    color: var(--accent-primary);
    border: var(--glass-border);
}

.btn-secondary:hover {
    background: var(--bg-card);
}

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

.image-frame {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    overflow: hidden;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: 3px solid rgba(255, 255, 255, 0.3);
    padding: 8px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    animation: glowPulse 3s ease-in-out infinite, glassFloat 6s ease-in-out infinite;
}

.image-placeholder {
    width: 100%;
    height: 100%;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    overflow: hidden;
}

.image-placeholder svg {
    width: 80px;
    height: 80px;
    color: var(--accent-primary);
    opacity: 0.5;
}

.image-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: inherit;
}

/* ========================================
   Sections Base
   ======================================== */

.section {
    padding: var(--space-3xl) var(--space-xl);
}

.section-alt {
    background: var(--bg-secondary);
    backdrop-filter: blur(10px);
}

.section-container {
    max-width: 1100px;
    margin: 0 auto;
}

.section-title {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--space-2xl);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.title-icon {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% 200%;
    animation: gradientRotate 4s ease infinite;
}

/* ========================================
   Honors and Awards
   ======================================== */

.honors-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.honor-item {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
}

.honor-item:hover {
    background: var(--bg-card);
    box-shadow: var(--shadow-md);
    transform: translateX(8px);
}

.honor-date {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent-secondary);
    font-weight: 500;
}

.honor-content {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
}

.honor-badge {
    display: inline-block;
    font-size: 0.7rem;
    padding: 3px 10px;
    border-radius: var(--radius-full);
    background: var(--accent-gradient);
    color: white;
    font-weight: 600;
    flex-shrink: 0;
}

.honor-title {
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.5;
}

.honor-detail {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: var(--space-xs);
}

/* ========================================
   Publications - Grouped List
   ======================================== */

.pub-summary {
    margin-bottom: var(--space-xl);
    padding: var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-lg);
    text-align: center;
}

.pub-summary-text {
    font-size: 1rem;
    color: var(--text-secondary);
}

.pub-summary-text strong {
    color: var(--text-primary);
}

.publications-grouped {
    display: flex;
    flex-direction: column;
    gap: var(--space-2xl);
}

.pub-group-title {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-sm);
    border-bottom: 2px solid var(--accent-primary);
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.pub-card {
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-md);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.pub-card:hover {
    transform: translateY(-4px) scale(1.01);
    box-shadow: var(--shadow-md), 0 0 20px rgba(99, 102, 241, 0.15);
    background: var(--bg-card);
}

.pub-num {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--accent-primary);
    font-weight: 600;
    padding-top: 2px;
}

.pub-text {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.pub-text a {
    color: var(--accent-primary);
}

.pub-text a:hover {
    color: var(--accent-secondary);
}

.pub-note {
    font-style: italic;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.pub-year {
    font-family: var(--font-display);
    font-size: 0.9rem;
    color: var(--accent-primary);
    font-weight: 600;
}

.pub-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--space-md);
    margin-bottom: var(--space-xs);
}

.pub-title {
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 600;
    line-height: 1.4;
    flex: 1;
    min-width: 0;
}

.pub-authors {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xs);
}

.pub-venue {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
}

.pub-links {
    display: flex;
    gap: var(--space-sm);
    flex-shrink: 0;
    white-space: nowrap;
}

.pub-link {
    font-size: 0.8rem;
    padding: var(--space-xs) var(--space-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    color: var(--accent-primary);
    transition: all 0.2s ease;
}

.pub-link:hover {
    background: var(--accent-gradient);
    color: white;
    transform: scale(1.05);
    box-shadow: 0 0 15px rgba(99, 102, 241, 0.3);
}

/* ========================================
   Key Research Contributions
   ======================================== */

.key-research-grid {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.research-card {
    display: grid;
    grid-template-columns: 380px 1fr;
    gap: var(--space-xl);
    padding: var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
}

.research-card:hover {
    background: var(--bg-card);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(99, 102, 241, 0.15);
    transform: translateY(-4px);
}

.research-card-image {
    position: relative;
    overflow: hidden;
}

.research-badge {
    background: rgba(99, 102, 241, 0.12);
    color: var(--accent-primary);
    padding: 10px 16px;
    text-align: center;
    font-weight: 700;
    font-size: 1.05rem;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    border-bottom: 1px solid rgba(99, 102, 241, 0.15);
}

.research-card-image img {
    width: 100%;
    display: block;
}

.research-card-body {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.research-title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 600;
    line-height: 1.5;
}

.research-title a {
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

.research-title a:hover {
    color: var(--accent-primary);
}

.research-authors {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.research-abstract {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.research-abstract summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--accent-primary);
    margin-bottom: var(--space-sm);
    font-size: 0.9rem;
}

.research-abstract summary:hover {
    color: var(--accent-secondary);
}

.research-abstract p {
    margin-top: var(--space-sm);
}

/* ========================================
   Talks
   ======================================== */

.talks-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.talk-item {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--space-xl);
    padding: var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    transition: all 0.3s ease;
    align-items: center;
}

.talk-item:hover {
    background: var(--bg-card);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.talk-photo {
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.talk-photo img {
    width: 100%;
    display: block;
    border-radius: var(--radius-lg);
}

.talk-info {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.talk-date {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent-secondary);
    font-weight: 500;
}

.talk-title {
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 600;
    line-height: 1.4;
}

.talk-location {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.talk-links {
    display: flex;
    gap: var(--space-sm);
    margin-top: var(--space-xs);
}

/* ========================================
   Experience - Glass Grid
   ======================================== */

.experience-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-2xl);
}

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

.exp-category {
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-sm);
    border-bottom: 2px solid var(--accent-primary);
}

.exp-category h3 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.exp-item {
    padding: var(--space-lg);
    margin-bottom: var(--space-md);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
}

.exp-item:hover {
    background: var(--bg-card);
    box-shadow: var(--shadow-md);
}

.exp-period {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--accent-secondary);
    margin-bottom: var(--space-xs);
    font-weight: 500;
}

.exp-title {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.exp-org {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ========================================
   Technical Expertise
   ======================================== */

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
}

.expertise-category {
    padding: var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    transition: all 0.3s ease;
}

.expertise-category:hover {
    background: var(--bg-card);
    box-shadow: var(--shadow-md);
}

.expertise-cat-title {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.expertise-items {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.expertise-item {
    padding: var(--space-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.expertise-label {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-xs);
}

.expertise-desc {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========================================
   Hobbies
   ======================================== */

.hobbies-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-xl);
}

.hobby-card {
    padding: var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.hobby-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.6s ease;
}

.hobby-card:hover::before {
    left: 150%;
}

.hobby-card:hover {
    background: var(--bg-card);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    transform: translateY(-6px);
}

.hobby-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
    color: white;
}

.hobby-name {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.hobby-desc {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.hobby-desc ul {
    margin: var(--space-sm) 0;
    padding-left: var(--space-xl);
}

.hobby-desc li {
    margin-bottom: var(--space-xs);
}

.hobby-desc a {
    color: var(--accent-primary);
}

.hobby-desc a:hover {
    color: var(--accent-secondary);
}

/* ========================================
   Contact - Glass Links
   ======================================== */

.contact-content {
    text-align: center;
    max-width: 750px;
    margin: 0 auto;
}

.contact-intro {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
}

.contact-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-md);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    transition: all 0.3s ease;
    cursor: pointer;
}

.contact-item:hover {
    background: var(--bg-card);
    color: var(--accent-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md), 0 0 20px rgba(99, 102, 241, 0.2);
    text-decoration: none;
}

.contact-item svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

/* ========================================
   Footer
   ======================================== */

.footer {
    padding: var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    text-align: center;
    border-top: var(--glass-border);
}

.footer-content p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ========================================
   Back to Top Button
   ======================================== */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    color: var(--accent-primary);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--accent-gradient);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg), 0 0 20px rgba(99, 102, 241, 0.4);
}

/* ========================================
   Animations
   ======================================== */

@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

@keyframes glowPulse {
    0%, 100% { box-shadow: 0 0 20px rgba(99, 102, 241, 0.3), 0 0 40px rgba(139, 92, 246, 0.2); }
    50% { box-shadow: 0 0 40px rgba(99, 102, 241, 0.5), 0 0 80px rgba(139, 92, 246, 0.3); }
}

@keyframes gradientRotate {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@keyframes glassFadeIn {
    from { opacity: 0; transform: translateY(30px); filter: blur(10px); }
    to { opacity: 1; transform: translateY(0); filter: blur(0); }
}

@keyframes scaleBlurIn {
    from { opacity: 0; transform: scale(0.9); filter: blur(8px); }
    to { opacity: 1; transform: scale(1); filter: blur(0); }
}

@keyframes glassFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

/* Hero element animations */
.hero-greeting { animation: glassFadeIn 0.7s ease-out forwards; animation-delay: 0.1s; opacity: 0; }
.hero-name { animation: glassFadeIn 0.8s ease-out forwards; animation-delay: 0.3s; opacity: 0; }
.hero-title { animation: glassFadeIn 0.7s ease-out forwards; animation-delay: 0.5s; opacity: 0; }
.hero-description { animation: glassFadeIn 0.7s ease-out forwards; animation-delay: 0.7s; opacity: 0; }
.hero-stats { animation: scaleBlurIn 0.6s ease-out forwards; animation-delay: 0.9s; opacity: 0; }
.hero-links { animation: glassFadeIn 0.6s ease-out forwards; animation-delay: 1.0s; opacity: 0; }
.hero-cta { animation: glassFadeIn 0.6s ease-out forwards; animation-delay: 1.1s; opacity: 0; }

/* ========================================
   Scroll-Triggered Animations
   ======================================== */

.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0);
}

.pub-card.scroll-animate,
.research-card.scroll-animate,
.honor-item.scroll-animate {
    opacity: 0;
    transform: translateY(30px) scale(0.95);
    filter: blur(5px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out, filter 0.5s ease-out;
}

.pub-card.scroll-animate.visible,
.research-card.scroll-animate.visible,
.honor-item.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0) scale(1);
    filter: blur(0);
}

.exp-item.scroll-animate {
    opacity: 0;
    transform: translateX(-20px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.exp-item.scroll-animate.visible {
    opacity: 1;
    transform: translateX(0);
}

.contact-item.scroll-animate {
    opacity: 0;
    transform: translateY(20px) scale(0.9);
    transition: opacity 0.4s ease-out, transform 0.4s ease-out;
}

.contact-item.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0) scale(1);
}

/* ========================================
   Navbar Scroll Effect
   ======================================== */

.navbar.scrolled {
    top: var(--space-sm);
    left: var(--space-lg);
    right: var(--space-lg);
    padding: 0;
    background: rgba(255, 255, 255, 0.15);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(99, 102, 241, 0.15);
}

[data-theme="dark"] .navbar.scrolled {
    background: rgba(30, 30, 50, 0.6);
}

.navbar.scrolled .nav-container {
    padding: var(--space-sm) var(--space-lg);
}

.navbar.scrolled .nav-logo {
    font-size: 1.1rem;
}

/* ========================================
   Theme Transition Animation
   ======================================== */

.theme-transitioning,
.theme-transitioning *,
.theme-transitioning *::before,
.theme-transitioning *::after {
    transition: background-color 0.5s ease,
                color 0.5s ease,
                border-color 0.5s ease,
                box-shadow 0.5s ease !important;
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 1024px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg-card);
        backdrop-filter: var(--glass-blur);
        border-radius: 0 0 var(--radius-lg) var(--radius-lg);
        border: var(--glass-border);
        border-top: none;
        padding: var(--space-sm);
        gap: 2px;
        z-index: 100;
    }

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

    .nav-links a {
        font-size: 0.85rem;
        padding: var(--space-sm) var(--space-md);
        border-radius: var(--radius-md);
    }

    .mobile-menu-toggle { display: inline-flex; }

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

    .hero-greeting, .hero-name, .hero-title { text-align: center; }
    .hero-description { text-align: left; }
    .hero-stats-box { align-self: center; }
    .hero-stats { justify-content: center; }
    .hero-links { justify-content: center; }
    .hero-cta { justify-content: center; }

    .hero-image { order: -1; }

    .image-frame { width: 250px; height: 250px; }

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

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

    .research-card-image {
        max-width: 500px;
        margin: 0 auto;
    }

    .talk-item {
        grid-template-columns: 1fr;
    }

    .talk-photo {
        max-width: 400px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    .navbar {
        left: var(--space-sm);
        right: var(--space-sm);
        border-radius: var(--radius-lg);
    }

    .hero {
        padding: 120px var(--space-md) var(--space-2xl);
    }

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

    .hero-stats {
        flex-direction: column;
        gap: var(--space-md);
        align-items: center;
    }

    .section {
        padding: var(--space-2xl) var(--space-md);
    }

    .pub-card {
        grid-template-columns: 30px 1fr;
    }

    .honor-item {
        grid-template-columns: 1fr;
    }

    .honor-date {
        margin-bottom: var(--space-xs);
    }

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

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

    .contact-item {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }

    .gradient-orb { animation: none; }
}

/* ---- Focus Styles ---- */
:focus-visible { outline: 2px solid var(--accent-primary); outline-offset: 3px; border-radius: 2px; }

/* ---- Skip Link ---- */
.skip-link { position: absolute; top: -40px; left: 0; background: var(--accent-primary); color: #fff; padding: 8px 16px; z-index: 9999; font-size: 0.875rem; transition: top 0.2s; }
.skip-link:focus { top: 0; }