/* ================================================================
   CLLT Lab Website - Modern Design System
   Bridging NLP, Theoretical Linguistics & Neural-Symbolic AI
   ================================================================ */

/* ===== CSS Variables ===== */
:root {
    /* Colors - University of Crete inspired */
    --color-primary: #1B3B6F;
    --color-primary-dark: #0F2847;
    --color-accent: #C4961A;
    --color-accent-dark: #9A7514;
    --color-text: #2C3E50;
    --color-text-light: #5A6C7D;
    --color-text-muted: #95A5B6;
    --color-bg: #FFFFFF;
    --color-bg-light: #F8F9FA;
    --color-bg-gray: #F5F5F5;
    --color-border: #E1E8ED;
    --color-border-light: #EDF2F7;
    --color-success: #27AE60;
    --color-warning: #F39C12;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Crimson Pro', Georgia, serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 4rem;
    --spacing-2xl: 6rem;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    --shadow-xl: 0 12px 40px rgba(0,0,0,0.15);
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    line-height: 1.7;
    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-family: var(--font-primary);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 600;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 600;
}

h4 {
    font-size: 1.25rem;
    font-weight: 600;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-light);
    line-height: 1.8;
}

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

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

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

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

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.container-wide {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===== Navigation ===== */
.navbar {
    background-color: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-sm);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 1rem;
    z-index: 1002;
}

.nav-brand .logo {
    height: 50px;
    width: auto;
    object-fit: contain;
}

.nav-brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin: 0;
    letter-spacing: -0.02em;
}

.nav-brand a {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: inherit;
    text-decoration: none;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1002;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
    transition: all var(--transition-base);
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu li {
    position: relative;
}

.nav-menu a {
    color: var(--color-text);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.5rem 0;
    transition: color var(--transition-fast);
    display: block;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--color-primary);
}

/* Dropdown */
.nav-dropdown {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 220px;
    padding: 0.5rem 0;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), 
                visibility var(--transition-base),
                transform var(--transition-base);
    z-index: 1001;
}

.nav-menu li:hover .nav-dropdown,
.nav-menu li:focus-within .nav-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.nav-dropdown li {
    list-style: none;
}

.nav-dropdown a {
    padding: 0.75rem 1.5rem;
    color: var(--color-text);
    font-size: 0.9rem;
    font-weight: 400;
    white-space: nowrap;
}

.nav-dropdown a:hover {
    background: var(--color-bg-light);
    color: var(--color-primary);
}

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    padding: var(--spacing-2xl) 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><text x="10" y="50" font-family="Georgia" font-size="40" fill="rgba(255,255,255,0.03)">Α Β Γ Δ</text></svg>');
    opacity: 0.5;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero h1 {
    color: white;
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    line-height: 1.1;
}

.hero .subtitle {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    margin-bottom: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.95);
    font-weight: 400;
}

.hero .meta {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--spacing-lg);
}

.hero-cta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: var(--spacing-lg);
}

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--color-accent-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: white;
}

/* ===== Stats Bar ===== */
.stats-bar {
    background: var(--color-bg-light);
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--color-border);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    text-align: center;
}

.stat-item {
    padding: var(--spacing-md);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--color-text-light);
    font-weight: 500;
}

/* ===== Section Styles ===== */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-alt {
    background: var(--color-bg-light);
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-xl);
}

.section-title {
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ===== Card Styles ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.card {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-base);
    border: 1px solid var(--color-border-light);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.card-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--color-bg-gray);
}

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

.card:hover .card-image img {
    transform: scale(1.1);
}

.card-body {
    padding: var(--spacing-lg);
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.card-meta {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.card-text {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}

.card-footer {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

/* ===== Publication Card ===== */
.publication-card {
    background: var(--color-bg);
    border-left: 4px solid var(--color-primary);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.publication-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.publication-title {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.publication-authors {
    color: var(--color-text-light);
    font-style: italic;
    margin-bottom: var(--spacing-xs);
    font-size: 0.95rem;
}

.publication-venue {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-md);
}

.publication-links {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.5rem 1rem;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.pub-link:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.pub-link.secondary {
    background: var(--color-bg-gray);
    color: var(--color-text);
}

.pub-link.secondary:hover {
    background: var(--color-border);
}

/* ===== Team Card ===== */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.team-card {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    border: 1px solid var(--color-border-light);
    transition: all var(--transition-base);
}

.team-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
}

.team-photo {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    margin: 0 auto var(--spacing-md);
    object-fit: cover;
    border: 4px solid var(--color-border-light);
}

.team-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.team-role {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: var(--spacing-sm);
}

.team-description {
    color: var(--color-text-light);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-md);
}

.team-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.team-links a {
    font-size: 0.875rem;
    padding: 0.5rem 1rem;
    background: var(--color-bg-light);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.team-links a:hover {
    background: var(--color-primary);
    color: white;
}

/* ===== Badge ===== */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.badge-primary {
    background: var(--color-primary);
    color: white;
}

.badge-accent {
    background: var(--color-accent);
    color: var(--color-primary-dark);
}

.badge-success {
    background: var(--color-success);
    color: white;
}

/* ===== News Timeline ===== */
.news-timeline {
    position: relative;
    padding-left: 2rem;
}

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

.news-item {
    position: relative;
    padding: var(--spacing-md) 0 var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.news-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: var(--spacing-md);
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-primary);
    border: 3px solid var(--color-bg);
    box-shadow: 0 0 0 3px var(--color-border);
}

.news-date {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: var(--spacing-xs);
}

.news-content {
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ===== Research Themes Grid ===== */
.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
}

.theme-card {
    background: var(--color-bg);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    border: 2px solid var(--color-border-light);
    transition: all var(--transition-base);
    cursor: pointer;
}

.theme-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.theme-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.theme-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
}

/* ===== Filters ===== */
.filters {
    background: var(--color-bg-light);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-xl);
}

.filter-group {
    margin-bottom: var(--spacing-md);
}

.filter-label {
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    display: block;
}

.filter-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.9rem;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

/* ===== Dataset Showcase ===== */
.dataset-showcase {
    background: linear-gradient(135deg, #F8F9FA 0%, #E9ECEF 100%);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-xl);
}

.dataset-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.dataset-title {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.dataset-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

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

.dataset-description {
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
    text-align: center;
    font-size: 1.1rem;
    color: var(--color-text-light);
}

.dataset-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

/* ===== Footer ===== */
footer {
    background: var(--color-text);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

footer p {
    color: rgba(255, 255, 255, 0.8);
    margin: 0;
}

.powered-by {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.powered-by-text {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.powered-by-logo {
    height: 40px;
    opacity: 0.9;
    transition: opacity var(--transition-base);
}

.powered-by-logo:hover {
    opacity: 1;
}

/* ===== Hero Modern (with image) ===== */
.hero-modern {
    position: relative;
    min-height: 400px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(27, 59, 111, 0.85) 0%, rgba(15, 40, 71, 0.9) 100%);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    color: white;
    text-align: center;
    padding: var(--spacing-2xl) 0;
}

.hero-content h1 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.hero-content .subtitle {
    color: rgba(255, 255, 255, 0.95);
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
}

/* ===== Research Grid ===== */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.research-card {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--color-border-light);
    transition: all var(--transition-base);
    text-align: center;
}

.research-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
}

.research-icon {
    width: 100%;
    height: 200px;
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: var(--spacing-md);
    background: var(--color-bg-gray);
}

.research-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.research-icon.tall {
    height: 400px;
    background: var(--color-bg-gray);
}

.research-icon.tall img {
    object-fit: cover;
}

.research-icon.cover {
    background: var(--color-bg-gray);
}

.dialect-icon {
    height: 428px;
    background: var(--color-bg-gray);
}

.dialect-icon img {
    object-fit: cover;
}

.research-section {
    padding: var(--spacing-2xl) 0;
}

.about-section {
    padding: var(--spacing-2xl) 0;
    background: var(--color-bg);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    margin-top: var(--spacing-lg);
}

.about-text {
    padding-right: var(--spacing-lg);
}

.about-image {
    border-radius: var(--radius-lg);
    overflow: hidden;
}

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

.content-section {
    max-width: 900px;
    margin: 0 auto;
}

.content-section h2 {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.highlight {
    background: var(--color-bg-light);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--color-primary);
}

/* ===== Responsive Design ===== */
@media (max-width: 968px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .card-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
    
    .about-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .about-text {
        padding-right: 0;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }
    
    /* Mobile Navigation */
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--color-bg);
        flex-direction: column;
        align-items: flex-start;
        padding: 5rem 2rem 2rem;
        gap: 0;
        box-shadow: -4px 0 20px rgba(0, 0, 0, 0.1);
        transition: right var(--transition-base);
        overflow-y: auto;
        z-index: 1001;
    }
    
    .nav-menu.active {
        right: 0;
    }
    
    .nav-menu li {
        width: 100%;
        border-bottom: 1px solid var(--color-border-light);
    }
    
    .nav-menu > li > a {
        padding: 1rem 0;
        font-size: 1rem;
        width: 100%;
    }
    
    /* Mobile Dropdown */
    .nav-dropdown {
        position: static;
        transform: none;
        opacity: 1;
        visibility: visible;
        box-shadow: none;
        border: none;
        border-radius: 0;
        padding: 0;
        margin-left: var(--spacing-md);
        margin-top: 0.5rem;
        margin-bottom: 0.5rem;
        min-width: auto;
        width: 100%;
        background: var(--color-bg-light);
        border-left: 3px solid var(--color-primary);
    }
    
    .nav-dropdown a {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }
    
    .nav-menu li.has-dropdown > a::after {
        content: '▾';
        float: right;
        transition: transform var(--transition-base);
    }
    
    .nav-menu li.has-dropdown.active > a::after {
        transform: rotate(180deg);
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .hero {
        padding: var(--spacing-xl) 0;
    }
    
    .hero-modern {
        min-height: 300px;
    }
    
    .card-grid,
    .team-grid,
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .team-photo {
        width: 120px;
        height: 120px;
    }
    
    .research-icon {
        height: 180px;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    .publication-links {
        flex-direction: column;
    }
    
    .pub-link {
        width: 100%;
        justify-content: center;
    }
    
    .dataset-stats {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .news-timeline {
        padding-left: 1.5rem;
    }
    
    .news-item {
        padding-left: var(--spacing-md);
    }
    
    .news-item::before {
        left: -1.75rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .nav-brand h1 {
        font-size: 1.25rem;
    }
    
    .nav-brand .logo {
        height: 40px;
    }
    
    .hero h1,
    .hero-content h1 {
        font-size: 2rem;
    }
    
    .hero .subtitle,
    .hero-content .subtitle {
        font-size: 1.1rem;
    }
    
    .section {
        padding: var(--spacing-lg) 0;
    }
    
    .hero-modern {
        min-height: 250px;
    }
    
    .stats-bar {
        padding: var(--spacing-md) 0;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .team-photo {
        width: 100px;
        height: 100px;
    }
    
    .research-icon {
        height: 150px;
    }
    
    .card-body {
        padding: var(--spacing-md);
    }
    
    .publication-card {
        padding: var(--spacing-md);
    }
    
    .dataset-showcase {
        padding: var(--spacing-md);
    }
    
    .filters {
        padding: var(--spacing-md);
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    h3 {
        font-size: 1.5rem;
    }
}

/* Touch-friendly improvements */
@media (hover: none) and (pointer: coarse) {
    .nav-menu a,
    .btn,
    .pub-link,
    .team-links a {
        min-height: 44px;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    .nav-dropdown a {
        min-height: 44px;
    }
    
    .filter-btn {
        min-height: 44px;
        padding: 0.75rem 1.25rem;
    }
}

/* ===== Utility Classes ===== */
.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

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

.font-serif { font-family: var(--font-serif); }
.font-mono { font-family: var(--font-mono); }