/* ============================================
   CSS Variables & Theme System
   ============================================ */
:root {
    /* Dark Theme (Default) */
    --bg-primary: #0a0f1a;
    --bg-secondary: #111827;
    --bg-tertiary: #1f2937;
    --bg-card: rgba(17, 24, 39, 0.8);
    --bg-card-hover: rgba(31, 41, 55, 0.9);
    
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    
    --accent-primary: #00d4aa;
    --accent-secondary: #00b894;
    --accent-glow: rgba(0, 212, 170, 0.3);
    
    --border-color: rgba(255, 255, 255, 0.1);
    --border-accent: rgba(0, 212, 170, 0.3);
    
    --gradient-hero: linear-gradient(135deg, #0a0f1a 0%, #1a1f3a 50%, #0a0f1a 100%);
    --gradient-card: linear-gradient(145deg, rgba(31, 41, 55, 0.5), rgba(17, 24, 39, 0.8));
    --gradient-accent: linear-gradient(135deg, #00d4aa, #00b894);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(0, 212, 170, 0.15);
    
    /* Typography */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Source Serif 4', Georgia, serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Spacing */
    --section-padding: 6rem;
    --container-max: 1200px;
    --nav-height: 80px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    --transition-theme: 0.4s ease;
}

/* Light Theme */
[data-theme="light"] {
    --bg-primary: #fafaf9;
    --bg-secondary: #f5f5f0;
    --bg-tertiary: #e7e5e4;
    --bg-card: rgba(255, 255, 255, 0.9);
    --bg-card-hover: rgba(255, 255, 255, 1);
    
    --text-primary: #1c1917;
    --text-secondary: #44403c;
    --text-muted: #78716c;
    
    --accent-primary: #059669;
    --accent-secondary: #047857;
    --accent-glow: rgba(5, 150, 105, 0.2);
    
    --border-color: rgba(0, 0, 0, 0.1);
    --border-accent: rgba(5, 150, 105, 0.3);
    
    --gradient-hero: linear-gradient(135deg, #fafaf9 0%, #f0fdf4 50%, #fafaf9 100%);
    --gradient-card: linear-gradient(145deg, rgba(255, 255, 255, 0.9), rgba(245, 245, 240, 0.8));
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 40px rgba(5, 150, 105, 0.1);
}

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

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

body {
    font-family: var(--font-body);
    font-size: 1.125rem;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-theme), color var(--transition-theme);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.3;
}

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

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

/* ============================================
   Animated Background
   ============================================ */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.bg-gradient {
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
    transition: background var(--transition-theme);
}

.bg-gradient::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 30%, var(--accent-glow) 0%, transparent 50%),
                radial-gradient(circle at 70% 70%, rgba(99, 102, 241, 0.1) 0%, transparent 50%);
    animation: bgFloat 20s ease-in-out infinite;
}

@keyframes bgFloat {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    33% { transform: translate(2%, 2%) rotate(1deg); }
    66% { transform: translate(-1%, 1%) rotate(-1deg); }
}

#particles-canvas {
    position: absolute;
    inset: 0;
    opacity: 0.6;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-md);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 2rem;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: transform var(--transition-fast);
}

.nav-logo:hover {
    transform: scale(1.05);
    color: var(--text-primary);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.5rem;
}

.nav-link {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: all var(--transition-fast);
    transform: translateX(-50%);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 60%;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Theme Toggle */
.theme-toggle {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    color: var(--text-secondary);
}

.theme-toggle:hover {
    background: var(--bg-card-hover);
    color: var(--accent-primary);
    transform: rotate(15deg);
}

.sun-icon { display: none; }
.moon-icon { display: block; }

[data-theme="light"] .sun-icon { display: block; }
[data-theme="light"] .moon-icon { display: none; }

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.hamburger span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
    transform-origin: center;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: calc(var(--nav-height) + 2rem) 2rem 2rem;
    position: relative;
}

.hero-content {
    max-width: var(--container-max);
    margin: 0 auto;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-greeting {
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--accent-primary);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.hero-name {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.name-first {
    display: block;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.name-last {
    display: block;
    color: var(--text-primary);
}

.hero-title {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.hero-title p {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

.title-line {
    flex: 1;
    height: 1px;
    background: var(--border-color);
    max-width: 60px;
}

.hero-tagline {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.separator {
    color: var(--accent-primary);
    margin: 0 0.25rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Profile Visual */
.hero-visual {
    display: flex;
    justify-content: center;
    position: relative;
}

.profile-frame {
    position: relative;
    width: 320px;
    height: 320px;
}

.profile-glow {
    position: absolute;
    inset: -20px;
    background: var(--gradient-accent);
    border-radius: 50%;
    opacity: 0.2;
    filter: blur(40px);
    animation: glowPulse 4s ease-in-out infinite;
}

@keyframes glowPulse {
    0%, 100% { opacity: 0.2; transform: scale(1); }
    50% { opacity: 0.3; transform: scale(1.05); }
}

.profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    position: relative;
    z-index: 2;
}

.profile-border {
    position: absolute;
    inset: -4px;
    border-radius: 50%;
    background: var(--gradient-accent);
    z-index: 1;
    animation: borderRotate 8s linear infinite;
}

@keyframes borderRotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.profile-border::before {
    content: '';
    position: absolute;
    inset: 4px;
    background: var(--bg-primary);
    border-radius: 50%;
}

.floating-badges {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.badge {
    position: absolute;
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    animation: badgeFloat 6s ease-in-out infinite;
}

.badge-1 {
    top: 10%;
    right: -10%;
    animation-delay: 0s;
}

.badge-2 {
    bottom: 20%;
    left: -15%;
    animation-delay: 2s;
}

.badge-3 {
    bottom: 5%;
    right: 5%;
    animation-delay: 4s;
}

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

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    font-family: var(--font-heading);
    font-size: 0.875rem;
    opacity: 0.7;
    animation: scrollBounce 2s ease-in-out infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--accent-primary);
    border-bottom: 2px solid var(--accent-primary);
    transform: rotate(45deg);
}

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

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    padding: 0.875rem 1.75rem;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-accent);
    color: #0a0f1a;
    box-shadow: var(--shadow-md), 0 0 20px var(--accent-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 30px var(--accent-glow);
    color: #0a0f1a;
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--accent-primary);
    border: 2px solid var(--accent-primary);
}

.btn-outline:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1.25rem 2.5rem;
    font-size: 1.125rem;
}

.btn svg {
    transition: transform var(--transition-fast);
}

.btn:hover svg {
    transform: translateX(4px);
}

/* ============================================
   Sections Base
   ============================================ */
.section {
    padding: var(--section-padding) 2rem;
    position: relative;
}

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

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.title-number {
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--accent-primary);
    font-weight: 400;
}

.section-intro {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin-bottom: 3rem;
}

/* ============================================
   About Section
   ============================================ */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
}

.about-intro {
    font-size: 1.35rem;
    color: var(--text-primary) !important;
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.highlight-item {
    display: flex;
    gap: 0.75rem;
    align-items: flex-start;
}

.highlight-icon {
    font-size: 1.5rem;
}

.highlight-item strong {
    display: block;
    font-family: var(--font-heading);
    font-size: 0.95rem;
    margin-bottom: 0.25rem;
}

.highlight-item p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin: 0;
}

.vision-card {
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    position: sticky;
    top: calc(var(--nav-height) + 2rem);
}

.vision-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.vision-icon {
    font-size: 1.75rem;
}

.vision-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.vision-card p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.8;
}

/* ============================================
   Research Section
   ============================================ */
.research-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}

.research-card {
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    border-color: var(--border-accent);
}

.research-card:hover::before {
    transform: scaleX(1);
}

.card-icon {
    width: 56px;
    height: 56px;
    background: var(--bg-tertiary);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: var(--accent-primary);
    transition: all var(--transition-base);
}

.research-card:hover .card-icon {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: scale(1.1);
}

.research-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.research-card p {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 1.5rem;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.card-tags span {
    font-family: var(--font-heading);
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.35rem 0.75rem;
    background: var(--bg-tertiary);
    border-radius: 50px;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

.research-card:hover .card-tags span {
    background: var(--accent-glow);
    color: var(--accent-primary);
}

/* ============================================
   Publications Section
   ============================================ */
.publications-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.filter-btn {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.6rem 1.25rem;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 50px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.filter-btn.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
}

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

.publication-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 2rem;
    padding: 2rem;
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    transition: all var(--transition-base);
}

.publication-item:hover {
    transform: translateX(8px);
    border-color: var(--border-accent);
    box-shadow: var(--shadow-md);
}

.publication-item.hidden {
    display: none;
}

.pub-year {
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--accent-primary);
    font-weight: 500;
}

.pub-title {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

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

.pub-venue {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: 1rem;
}

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

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--accent-primary);
    padding: 0.4rem 0.75rem;
    background: var(--bg-tertiary);
    border-radius: 8px;
    transition: all var(--transition-fast);
}

.pub-link:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
}

.publications-cta {
    text-align: center;
    margin-top: 3rem;
}

/* ============================================
   CV Section
   ============================================ */
.cv-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 4rem;
    align-items: start;
}

.cv-timeline {
    position: relative;
    padding-left: 2rem;
}

.cv-timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    padding-bottom: 3rem;
}

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

.timeline-marker {
    position: absolute;
    left: -2rem;
    top: 0;
    width: 12px;
    height: 12px;
    background: var(--accent-primary);
    border-radius: 50%;
    transform: translateX(-5px);
    box-shadow: 0 0 0 4px var(--bg-primary), 0 0 0 6px var(--accent-glow);
}

.timeline-date {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
    display: inline-block;
}

.timeline-content h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.timeline-org {
    font-family: var(--font-heading);
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.timeline-content p:last-child {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.download-card {
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2.5rem;
    text-align: center;
    position: sticky;
    top: calc(var(--nav-height) + 2rem);
}

.download-icon {
    color: var(--accent-primary);
    margin-bottom: 1.5rem;
}

.download-card h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1rem;
}

/* ============================================
   Contact Section
   ============================================ */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.contact-card {
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    padding: 1rem 0;
}

.contact-item:not(:last-child) {
    border-bottom: 1px solid var(--border-color);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
    flex-shrink: 0;
}

.contact-item h4 {
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.contact-item a,
.contact-item p {
    font-size: 1rem;
    color: var(--text-primary);
}

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

.social-link {
    width: 48px;
    height: 48px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(-4px);
}

.contact-message {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 4rem 2rem 2rem;
}

.footer-content {
    max-width: var(--container-max);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 3rem;
    align-items: center;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.footer-brand {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--text-primary);
}

.footer-brand p {
    font-family: var(--font-body);
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.footer-nav {
    display: flex;
    gap: 2rem;
}

.footer-nav a {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.footer-nav a:hover {
    color: var(--accent-primary);
}

.footer-social {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

.footer-social a {
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

.footer-social a:hover {
    color: var(--accent-primary);
    transform: translateY(-2px);
}

.footer-bottom {
    max-width: var(--container-max);
    margin: 0 auto;
    padding-top: 2rem;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

/* ============================================
   Reveal Animations
   ============================================ */
.reveal-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal-scale {
    opacity: 0;
    transform: scale(0.95);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal-up.revealed,
.reveal-scale.revealed {
    opacity: 1;
    transform: translateY(0) scale(1);
}

.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 3rem;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .hero-title {
        justify-content: center;
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .profile-frame {
        width: 250px;
        height: 250px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-highlights {
        grid-template-columns: 1fr;
    }
    
    .vision-card {
        position: static;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .cv-content {
        grid-template-columns: 1fr;
    }
    
    .download-card {
        position: static;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .footer-nav {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .footer-social {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 4rem;
        --nav-height: 70px;
    }
    
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        height: 100vh;
        background: var(--bg-primary);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2rem;
        transition: right var(--transition-base);
    }
    
    .nav-menu.active {
        right: 0;
    }
    
    .nav-link {
        font-size: 1.25rem;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero-name {
        font-size: clamp(2rem, 8vw, 3rem);
    }
    
    .floating-badges {
        display: none;
    }
    
    .publication-item {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .pub-year {
        font-size: 0.875rem;
    }
    
    .section-title {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .hero-cta {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 1rem;
    }
    
    .section {
        padding: 3rem 1rem;
    }
    
    .nav-container {
        padding: 0 1rem;
    }
    
    .profile-frame {
        width: 200px;
        height: 200px;
    }
    
    .research-card,
    .publication-item,
    .contact-card,
    .vision-card,
    .download-card {
        padding: 1.5rem;
    }
    
    .publications-filter {
        gap: 0.5rem;
    }
    
    .filter-btn {
        font-size: 0.8rem;
        padding: 0.5rem 1rem;
    }
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
    .bg-animation,
    .navbar,
    .scroll-indicator,
    .theme-toggle,
    .floating-badges {
        display: none !important;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .section {
        padding: 2rem 0;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
}