/* ==================== CSS Variables - Design System ==================== */
:root {
    /* Color Palette */
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --secondary: #ec4899;
    --secondary-dark: #db2777;
    --accent: #8b5cf6;
    --accent-dark: #7c3aed;
    
    /* Neutral Colors */
    --text-dark: #1e293b;
    --text-medium: #475569;
    --text-light: #64748b;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-gray: #f1f5f9;
    --border: #e2e8f0;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    --gradient-hero: linear-gradient(135deg, rgba(59, 130, 246, 0.85) 0%, rgba(139, 92, 246, 0.85) 50%, rgba(236, 72, 153, 0.85) 100%);
    --gradient-card: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    --gradient-overlay: linear-gradient(135deg, rgba(59, 130, 246, 0.9) 0%, rgba(139, 92, 246, 0.9) 50%, rgba(236, 72, 153, 0.9) 100%);
    
    /* Typography */
    --font-chinese: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-english: 'Montserrat', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    --space-3xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.2);
    --shadow-hover: 0 15px 35px rgba(59, 130, 246, 0.25);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Unified Hover Effect */
    --hover-lift: translateY(-8px);
    --hover-scale: scale(1.02);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-chinese);
    color: var(--text-dark);
    line-height: 1.6;
    background: var(--bg-white);
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* ==================== Container ==================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* ==================== Navigation ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: box-shadow var(--transition-normal);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-sm) var(--space-lg);
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.nav-link {
    font-weight: 500;
    color: var(--text-dark);
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-normal);
}

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

.nav-link:hover::after {
    width: 100%;
}

.nav-link-cta {
    background: var(--gradient-primary);
    color: white !important;
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.nav-link-cta::after {
    display: none;
}

.nav-link-cta:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-xs);
}

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

/* ==================== Hero Section ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: url('../images/astronaut_in\ HK_square.jpg') center/cover no-repeat;
    padding: 120px 0 var(--space-3xl);
}

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

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

.organizers-logos {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.logo-card {
    background: white;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.logo-card img {
    height: 50px;
    width: auto;
}

.hero-content {
    color: white;
    max-width: 800px;
}

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

.title-zh {
    display: block;
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: var(--space-xs);
}

.title-en {
    display: block;
    font-family: var(--font-english);
    font-size: clamp(1.5rem, 5vw, 2.5rem);
    font-weight: 700;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    font-weight: 600;
    margin-bottom: var(--space-sm);
    opacity: 0.95;
}

.hero-tagline {
    font-size: 1.2rem;
    font-style: italic;
    margin-bottom: var(--space-md);
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: var(--space-md);
    opacity: 0.95;
}

.hero-deadline {
    font-size: 1.2rem;
    font-weight: 700;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(5px);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    display: inline-block;
    margin-bottom: var(--space-lg);
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.hero-buttons {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
    margin-bottom: var(--space-xl);
}

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

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

.stat-number {
    font-size: 3rem;
    font-weight: 900;
    line-height: 1;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
    margin-top: var(--space-xs);
}

/* ==================== Buttons ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-sm) var(--space-lg);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--secondary);
    color: white;
    transform: var(--hover-lift);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary);
    transform: var(--hover-lift);
}

/* ==================== Sections ==================== */
.section {
    padding: var(--space-3xl) 0;
}

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

/* Section with KV Background - No color mask, just subtle dark overlay for readability */
.section-kv-bg {
    position: relative;
    background: url('../images/astronaut_in\ HK_square.jpg') center/cover no-repeat fixed;
}

.section-kv-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
}

.section-kv-bg .container {
    position: relative;
    z-index: 1;
}

.section-kv-bg .section-title {
    background: white;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.section-kv-bg .section-subtitle {
    color: rgba(255, 255, 255, 0.95);
    text-shadow: 0 1px 5px rgba(0, 0, 0, 0.3);
}

/* Section with Formats Background - New astronaut image */
.section-formats-bg {
    position: relative;
    background: url('../images/AIFest_KVimage2.jpg') center/cover no-repeat fixed;
}

.section-formats-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
}

.section-formats-bg .container {
    position: relative;
    z-index: 1;
}

.section-formats-bg .section-title {
    background: white;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.section-formats-bg .section-subtitle {
    color: rgba(255, 255, 255, 0.95);
    text-shadow: 0 1px 5px rgba(0, 0, 0, 0.3);
}

.section-title {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 900;
    text-align: center;
    margin-bottom: var(--space-sm);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: var(--space-xl);
}

/* ==================== Vision Section - Stacked Layout ==================== */
.vision-content {
    max-width: 800px;
    margin: 0 auto var(--space-xl);
    text-align: center;
}

.vision-text {
    font-size: 1.2rem;
    line-height: 2;
    color: var(--text-medium);
}

/* Stacked info cards for 主辦單位 and 業界伙伴 */
.info-cards-stacked {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
    max-width: 900px;
    margin: 0 auto;
}

.info-card {
    background: white;
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.info-card:hover {
    transform: var(--hover-lift);
    box-shadow: var(--shadow-hover);
}

.info-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--space-md);
    text-align: center;
}

.info-card-text {
    color: var(--text-medium);
    line-height: 1.8;
    text-align: center;
}

/* Partner logos grid - flexible for adding more */
.partner-logos-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-md) 0;
}

.partner-logo-item {
    background: var(--bg-light);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.partner-logo-item:hover {
    transform: var(--hover-lift);
    box-shadow: var(--shadow-md);
}

.partner-logo-item img {
    max-height: 60px;
    width: auto;
}

/* Organizer logos grid */
.organizer-logos-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-md) 0;
}

.organizer-logo-item {
    background: var(--bg-light);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.organizer-logo-item:hover {
    transform: var(--hover-lift);
    box-shadow: var(--shadow-md);
}

.organizer-logo-item img {
    max-height: 60px;
    width: auto;
}

/* ==================== Card Grid System ==================== */
.card-grid {
    display: grid;
    gap: var(--space-lg);
}

.card-grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.card-grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* Judges grid - 3 on top, 4 on bottom */
.card-grid-judges {
    display: grid;
    gap: var(--space-lg);
    max-width: 900px;
    margin: 0 auto;
}

.judges-row-top {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.judges-row-bottom {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
}

/* ==================== Unified Card Styles with Hover Effects ==================== */
.card {
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal), background var(--transition-normal);
}

/* Unified Hover Effect for All Cards */
.card:hover {
    transform: var(--hover-lift);
    box-shadow: var(--shadow-hover);
}

/* Gradient Card (for pillars, categories) */
.card-gradient {
    background: var(--gradient-card);
    color: white;
}

.card-gradient:hover {
    background: linear-gradient(135deg, var(--accent) 0%, var(--secondary) 100%);
    box-shadow: 0 15px 35px rgba(139, 92, 246, 0.35);
}

.card-gradient .card-title {
    color: white;
}

.card-gradient .card-description {
    color: rgba(255, 255, 255, 0.9);
}

/* Light Card (for training) */
.card-light {
    background: white;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-md);
}

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

.card-light .card-title {
    color: var(--text-dark);
}

.card-light .card-description {
    color: var(--text-medium);
}

/* Score Card (for evaluation) */
.card-score {
    background: var(--gradient-card);
    color: white;
    text-align: center;
}

.card-score:hover {
    background: linear-gradient(135deg, var(--accent) 0%, var(--secondary) 100%);
    box-shadow: 0 15px 35px rgba(139, 92, 246, 0.35);
}

.score-number {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: var(--space-sm);
}

/* Judge Card - Larger size */
.card-judge {
    background: white;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    text-align: center;
    padding: var(--space-xl);
}

.card-judge:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-hover);
}

.judge-avatar {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--space-md);
    background: var(--gradient-card);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform var(--transition-normal);
}

.card-judge:hover .judge-avatar {
    transform: scale(1.1);
}

.card-judge .card-title {
    font-size: 1.3rem;
    margin-bottom: var(--space-xs);
}

.card-judge .card-description {
    font-size: 1rem;
}

/* Card Elements */
.card-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
    transition: transform var(--transition-normal);
}

.card:hover .card-icon {
    transform: scale(1.15);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.card-description {
    line-height: 1.6;
    margin-bottom: var(--space-sm);
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-top: var(--space-sm);
}

.tag {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    transition: background var(--transition-fast);
}

.card:hover .tag {
    background: rgba(255, 255, 255, 0.3);
}

.card-list {
    margin-top: var(--space-sm);
}

.card-list li {
    padding: var(--space-xs) 0;
    padding-left: var(--space-md);
    position: relative;
    color: var(--text-medium);
}

.card-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
}

/* ==================== Format Cards with Unified Hover ==================== */
.format-card {
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-bottom: var(--space-lg);
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.format-card:hover {
    transform: var(--hover-lift);
    box-shadow: var(--shadow-hover);
}

.format-primary {
    background: linear-gradient(135deg, var(--accent) 0%, var(--secondary) 100%);
}

.format-primary:hover {
    box-shadow: 0 15px 35px rgba(236, 72, 153, 0.35);
}

.format-secondary {
    background: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
}

.format-secondary:hover {
    box-shadow: 0 15px 35px rgba(249, 115, 22, 0.35);
}

.format-accent {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
}

.format-accent:hover {
    box-shadow: 0 15px 35px rgba(139, 92, 246, 0.35);
}

.format-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
    flex-wrap: wrap;
}

.format-badge {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.9rem;
    transition: background var(--transition-fast);
}

.format-card:hover .format-badge {
    background: rgba(255, 255, 255, 0.3);
}

.format-title {
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.format-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
}

.format-requirements h4,
.format-example h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: white;
}

.format-requirements ul {
    margin-bottom: var(--space-md);
}

.format-requirements li {
    padding: var(--space-xs) 0;
    color: rgba(255, 255, 255, 0.95);
    line-height: 1.6;
}

.example-title {
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: white;
}

.example-embed {
    margin-bottom: var(--space-md);
}

.example-embed iframe {
    border-radius: var(--radius-sm);
    width: 100%;
}

/* ==================== Timeline with Hover ==================== */
.timeline {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: white;
    border-radius: var(--radius-md);
    margin-left: var(--space-sm);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.timeline-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

.timeline-marker {
    position: absolute;
    left: -41px;
    top: var(--space-md);
    width: 16px;
    height: 16px;
    border-radius: var(--radius-full);
    background: var(--primary);
    border: 3px solid white;
    box-shadow: 0 0 0 3px var(--primary);
    transition: transform var(--transition-normal);
}

.timeline-item:hover .timeline-marker {
    transform: scale(1.3);
}

.timeline-item:nth-child(even) .timeline-marker {
    background: var(--secondary);
    box-shadow: 0 0 0 3px var(--secondary);
}

.timeline-date {
    font-weight: 600;
    color: var(--primary);
    margin-bottom: var(--space-xs);
}

.timeline-item:nth-child(even) .timeline-date {
    color: var(--secondary);
}

.timeline-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
    color: var(--text-dark);
}

.timeline-description {
    color: var(--text-light);
    line-height: 1.6;
}

/* ==================== Awards with Hover ==================== */
.awards-card {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 2px solid var(--primary);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.awards-card:hover {
    transform: var(--hover-lift);
    box-shadow: var(--shadow-hover);
    border-color: var(--secondary);
}

.awards-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: var(--space-md);
}

.awards-list li {
    padding: var(--space-sm) 0;
    padding-left: var(--space-lg);
    position: relative;
    color: var(--text-medium);
    border-bottom: 1px solid var(--border);
}

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

.awards-list li::before {
    content: '🏆';
    position: absolute;
    left: 0;
}

/* ==================== FAQ with Hover ==================== */
.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    border-radius: var(--radius-md);
    margin-bottom: var(--space-sm);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    border: 1px solid var(--border);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
}

.faq-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.faq-question {
    width: 100%;
    padding: var(--space-md);
    background: none;
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background var(--transition-fast);
}

.faq-question:hover {
    background: var(--bg-light);
}

.faq-icon {
    width: 24px;
    height: 24px;
    position: relative;
    flex-shrink: 0;
}

.faq-icon::before,
.faq-icon::after {
    content: '';
    position: absolute;
    background: var(--primary);
    transition: transform var(--transition-normal);
}

.faq-icon::before {
    width: 2px;
    height: 12px;
    left: 11px;
    top: 6px;
}

.faq-icon::after {
    width: 12px;
    height: 2px;
    left: 6px;
    top: 11px;
}

.faq-item.active .faq-icon::before {
    transform: rotate(90deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal), padding var(--transition-normal);
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 var(--space-md) var(--space-md);
}

.faq-answer p {
    margin-bottom: var(--space-sm);
    color: var(--text-medium);
    line-height: 1.8;
}

.faq-answer ul {
    margin: var(--space-sm) 0;
    padding-left: var(--space-md);
}

.faq-answer li {
    margin-bottom: var(--space-xs);
    color: var(--text-medium);
}

.faq-note {
    background: var(--bg-light);
    padding: var(--space-sm);
    border-left: 4px solid var(--primary);
    border-radius: var(--radius-sm);
    margin-top: var(--space-sm);
}

/* ==================== Training Video Section ==================== */
.training-video-section {
    margin-top: var(--space-xl);
    padding: var(--space-xl);
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.training-video-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--space-sm);
}

.training-video-description {
    font-size: 1.1rem;
    color: var(--text-medium);
    margin-bottom: var(--space-lg);
}

.training-video-container {
    position: relative;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
}

.training-video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

/* ==================== Registration ==================== */
.registration-container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    min-height: 600px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.registration-container iframe {
    width: 100%;
    min-height: 600px;
    border: none;
}

/* ==================== Footer ==================== */
.footer {
    background: var(--text-dark);
    color: white;
    padding: var(--space-xl) 0 var(--space-md);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.footer-text {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
    margin-bottom: var(--space-sm);
}

.footer-subtitle {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
    margin-bottom: var(--space-xs);
}

.footer-logo-grid {
    display: flex;
    gap: var(--space-sm);
}

.footer-logo-grid img {
    filter: brightness(0) invert(1);
    opacity: 0.8;
}

.footer-links li {
    margin-bottom: var(--space-xs);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast), transform var(--transition-fast);
    display: inline-block;
}

.footer-links a:hover {
    color: white;
    transform: translateX(5px);
}

.footer-contact li {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--space-xs);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* ==================== Back to Top Button ==================== */
.back-to-top {
    position: fixed;
    bottom: var(--space-lg);
    right: var(--space-lg);
    width: 50px;
    height: 50px;
    border-radius: var(--radius-full);
    background: var(--gradient-primary);
    color: white;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: scale(1.15) translateY(-3px);
    box-shadow: var(--shadow-lg);
}

/* ==================== Responsive Design ==================== */
@media (max-width: 992px) {
    .judges-row-top {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .judges-row-bottom {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 60px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: var(--transition-normal);
        box-shadow: var(--shadow-md);
        padding: var(--space-lg) 0;
        gap: var(--space-sm);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

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

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

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

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

    .btn {
        width: 100%;
    }

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

    .card-grid-4,
    .card-grid-3 {
        grid-template-columns: 1fr;
    }

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

    .stat-number {
        font-size: 2.5rem;
    }
    
    .judges-row-top,
    .judges-row-bottom {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-sm);
    }

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

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

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

    .organizers-logos {
        justify-content: center;
    }

    .timeline {
        padding-left: 30px;
    }

    .timeline::before {
        left: 10px;
    }

    .timeline-marker {
        left: -25px;
        width: 12px;
        height: 12px;
    }
    
    .judges-row-top,
    .judges-row-bottom {
        grid-template-columns: 1fr;
    }
    
    .judge-avatar {
        width: 80px;
        height: 80px;
    }
}

/* ==================== Animations ==================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-on-scroll {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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