/* ==========================================================================
   AI Research HK - Styles
   Hong Kong AI Information Platform
   ========================================================================== */

/* CSS Variables */
:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #06b6d4;
    --accent: #f59e0b;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;

    /* Neutrals */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* Text */
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #ffffff;

    /* Background */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --gradient-secondary: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
    --gradient-dark: linear-gradient(135deg, #1f2937 0%, #111827 100%);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans TC", "Microsoft JhengHei", sans-serif;
    --font-mono: "SF Mono", Monaco, "Noto Sans Mono CJK TC", monospace;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;

    /* Container */
    --container-max: 1200px;
}

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

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

ul, ol {
    list-style: none;
}

input, textarea {
    font-family: inherit;
    font-size: inherit;
}

/* ==========================================================================
   Utilities
   ========================================================================== */

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-3xl) 0;
}

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

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.section-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.subsection-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--text-light);
    box-shadow: var(--shadow-md);
}

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

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

.btn-secondary:hover {
    background: var(--primary);
    color: var(--text-light);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--gray-300);
}

.btn-outline:hover {
    border-color: var(--primary);
    background: var(--primary);
    color: var(--text-light);
}

/* ==========================================================================
   Header
   ========================================================================== */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    transition: all var(--transition-base);
}

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

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    font-size: 2rem;
}

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

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

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

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

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

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

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-sm);
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

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

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

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

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 70px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: var(--gradient-dark);
    z-index: -2;
}

.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(139, 92, 246, 0.2) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.hero-content {
    text-align: center;
    color: var(--text-light);
    max-width: 900px;
    width: 100%;
    padding: var(--space-xl);
}

.hero-subtitle {
    display: block;
    font-size: 1rem;
    font-weight: 500;
    color: var(--secondary);
    margin-bottom: var(--space-md);
    letter-spacing: 2px;
    text-transform: uppercase;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--space-lg);
    background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.25rem;
    color: var(--gray-300);
    margin-bottom: var(--space-2xl);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

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

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--gray-400);
    margin-top: var(--space-xs);
}

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

.hero-scroll {
    position: absolute;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--gray-400);
    font-size: 0.875rem;
}

.scroll-indicator {
    width: 24px;
    height: 40px;
    border: 2px solid var(--gray-400);
    border-radius: var(--radius-full);
    margin: var(--space-sm) auto 0;
    position: relative;
}

.scroll-indicator::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--gray-400);
    border-radius: var(--radius-full);
    animation: scrollDown 2s ease-in-out infinite;
}

@keyframes scrollDown {
    0%, 100% { top: 8px; opacity: 1; }
    50% { top: 20px; opacity: 0.3; }
}

/* ==========================================================================
   News Ticker
   ========================================================================== */

.news-ticker {
    background: var(--primary);
    color: var(--text-light);
    padding: var(--space-sm) 0;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.ticker-label {
    background: var(--primary-dark);
    padding: var(--space-xs) var(--space-md);
    font-weight: 600;
    font-size: 0.875rem;
    white-space: nowrap;
}

.ticker-content {
    flex: 1;
    overflow: hidden;
}

.ticker-track {
    display: flex;
    animation: ticker 30s linear infinite;
}

.ticker-item {
    white-space: nowrap;
    padding: 0 var(--space-2xl);
    font-size: 0.875rem;
}

@keyframes ticker {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* ==========================================================================
   News Section
   ========================================================================== */

.news-filter {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
}

.filter-btn {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--bg-primary);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

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

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

.news-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.news-card.featured {
    grid-column: span 2;
}

.news-card.featured .news-image {
    height: 100%;
    min-height: 280px;
}

.news-card.hidden {
    display: none;
}

.news-card-link-wrapper {
    display: block;
    text-decoration: none;
    color: inherit;
    height: 100%;
}

.news-card.featured .news-card-link-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    height: 100%;
}

.news-card:not(.featured) .news-card-link-wrapper {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.news-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.news-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-secondary);
    font-size: 4rem;
}

.news-badge {
    position: absolute;
    top: var(--space-md);
    left: var(--space-md);
    background: var(--error);
    color: var(--text-light);
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
}

.news-content {
    padding: var(--space-lg);
}

.news-meta {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-sm);
    font-size: 0.875rem;
}

.news-category {
    color: var(--primary);
    font-weight: 500;
}

.news-date {
    color: var(--text-secondary);
}

.news-title {
    font-size: 1.25rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.news-card:hover .news-title {
    color: var(--primary);
}

.news-excerpt {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: var(--space-md);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-link {
    color: var(--primary);
    font-weight: 500;
    font-size: 0.875rem;
}

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

.load-more {
    text-align: center;
    margin-top: var(--space-xl);
}

/* ==========================================================================
   GenAI Section
   ========================================================================== */

.models-comparison {
    margin-bottom: var(--space-3xl);
}

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

.model-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    position: relative;
    transition: all var(--transition-base);
}

.model-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.model-logo {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--space-md);
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-light);
}

.model-logo.claude-logo {
    background: linear-gradient(135deg, #d97706 0%, #f59e0b 100%);
}

.model-logo.gemini-logo {
    background: linear-gradient(135deg, #4285f4 0%, #34a853 50%, #ea4335 100%);
}

.model-logo.llama-logo {
    background: linear-gradient(135deg, #0668e1 0%, #1877f2 100%);
}

.model-name {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-xs);
}

.model-company {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.model-stats {
    margin-bottom: var(--space-md);
}

.model-stat {
    margin-bottom: var(--space-sm);
}

.model-stat .stat-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xs);
    text-align: left;
}

.stat-bar {
    height: 6px;
    background: var(--gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.stat-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

.model-badge {
    position: absolute;
    top: var(--space-md);
    right: var(--space-md);
    background: var(--gray-100);
    color: var(--text-secondary);
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
}

.model-badge.highlight {
    background: var(--primary);
    color: var(--text-light);
}

/* GenAI Apps */
.apps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.app-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.app-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.app-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.app-card h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.app-card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

/* ==========================================================================
   Trends Section
   ========================================================================== */

.trends-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
}

.trend-chart-container {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.chart-wrapper {
    margin-top: var(--space-lg);
}

.chart {
    padding: var(--space-lg);
}

.chart-bars {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    height: 300px;
    padding-bottom: var(--space-xl);
    border-bottom: 2px solid var(--gray-200);
}

.chart-bar-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex: 1;
}

.chart-bar {
    width: 50px;
    background: var(--gradient-secondary);
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    position: relative;
    transition: all var(--transition-base);
}

.chart-bar:hover {
    opacity: 0.9;
    transform: scaleY(1.02);
    transform-origin: bottom;
}

.chart-bar.active {
    background: var(--gradient-primary);
}

.chart-bar.projected {
    background: var(--gray-300);
    background-image: repeating-linear-gradient(
        45deg,
        transparent,
        transparent 5px,
        rgba(255,255,255,0.3) 5px,
        rgba(255,255,255,0.3) 10px
    );
}

.bar-value {
    position: absolute;
    top: -30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
}

.bar-label {
    margin-top: var(--space-sm);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.chart-note {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: var(--space-md);
}

/* Key Trends */
.trends-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.trend-item {
    display: flex;
    gap: var(--space-lg);
    padding: var(--space-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

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

.trend-number {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    min-width: 50px;
}

.trend-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-xs);
}

.trend-content p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

/* ==========================================================================
   Learning Section
   ========================================================================== */

.learning-paths {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    margin-bottom: var(--space-3xl);
}

.path-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    transition: all var(--transition-base);
}

.path-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.path-card.featured {
    border: 2px solid var(--primary);
    position: relative;
}

.path-card.featured::before {
    content: '推薦';
    position: absolute;
    top: -12px;
    right: var(--space-lg);
    background: var(--primary);
    color: var(--text-light);
    padding: var(--space-xs) var(--space-md);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
}

.path-level {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-md);
    width: fit-content;
}

.path-level.beginner {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.path-level.intermediate {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
}

.path-level.advanced {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
}

.path-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.path-topics {
    flex: 1;
    margin-bottom: var(--space-lg);
}

.path-topics li {
    padding: var(--space-sm) 0;
    color: var(--text-secondary);
    font-size: 0.9375rem;
    border-bottom: 1px solid var(--gray-100);
    position: relative;
    padding-left: var(--space-lg);
}

.path-topics li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success);
    font-weight: 600;
}

.path-info {
    display: flex;
    gap: var(--space-lg);
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

/* Glossary */
.glossary-section {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-md);
}

.glossary-search {
    margin-bottom: var(--space-lg);
}

.search-input {
    width: 100%;
    padding: var(--space-md) var(--space-lg);
    font-size: 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

.glossary-item {
    background: var(--bg-secondary);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.glossary-item:hover {
    background: var(--gray-100);
}

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

.glossary-item h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: var(--space-xs);
}

.glossary-item p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ==========================================================================
   Newsletter Section
   ========================================================================== */

.newsletter-section {
    background: var(--gradient-primary);
    padding: var(--space-3xl) 0;
}

.newsletter-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
    color: var(--text-light);
}

.newsletter-content h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.newsletter-content p {
    margin-bottom: var(--space-lg);
    opacity: 0.9;
}

.newsletter-form {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.newsletter-input {
    flex: 1;
    padding: var(--space-md) var(--space-lg);
    font-size: 1rem;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.95);
}

.newsletter-input:focus {
    outline: none;
    border-color: var(--secondary);
}

.newsletter-form .btn-primary {
    background: var(--gray-900);
    flex-shrink: 0;
}

.newsletter-note {
    font-size: 0.875rem;
    opacity: 0.8;
}

/* ==========================================================================
   SEO Section
   ========================================================================== */

.seo-section {
    background: var(--bg-secondary);
    padding: var(--space-3xl) 0;
}

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

.seo-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

.seo-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-top: var(--space-xl);
    margin-bottom: var(--space-md);
}

.seo-content p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    line-height: 1.8;
}

.seo-content ul {
    margin-bottom: var(--space-md);
    padding-left: var(--space-lg);
}

.seo-content li {
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
    line-height: 1.8;
    position: relative;
    padding-left: var(--space-md);
}

.seo-content li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
}

.seo-content strong {
    color: var(--text-primary);
}

.seo-cta {
    font-size: 1.125rem;
    color: var(--primary) !important;
    font-weight: 500;
    margin-top: var(--space-xl);
}

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

.footer {
    background: var(--bg-dark);
    color: var(--gray-300);
    padding: var(--space-3xl) 0 var(--space-lg);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand .logo {
    margin-bottom: var(--space-md);
}

.footer-brand .logo-text {
    color: var(--text-light);
}

.footer-brand p {
    font-size: 0.9375rem;
    line-height: 1.7;
}

.footer-links h4 {
    color: var(--text-light);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

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

.footer-links a {
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-lg);
    border-top: 1px solid var(--gray-700);
    font-size: 0.875rem;
}

.footer-social {
    display: flex;
    gap: var(--space-md);
}

.footer-social a {
    font-size: 1.25rem;
    transition: transform var(--transition-base);
}

.footer-social a:hover {
    transform: scale(1.2);
}

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

.back-to-top {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    width: 50px;
    height: 50px;
    background: var(--primary);
    color: var(--text-light);
    border-radius: var(--radius-full);
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

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

@media (max-width: 1024px) {
    .news-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .news-card.featured {
        grid-column: span 2;
    }

    .models-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .apps-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .learning-paths {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 768px) {
    .nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: var(--space-lg);
        gap: var(--space-md);
        border-bottom: 1px solid var(--gray-200);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }

    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-title {
        font-size: 2.25rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-lg);
    }

    .stat-number {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

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

    .news-card.featured {
        grid-column: span 1;
        grid-template-columns: 1fr;
    }

    .news-card.featured .news-card-link-wrapper {
        display: block;
        grid-template-columns: 1fr;
    }

    .news-card.featured .news-image {
        height: 200px;
    }

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

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

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

    .newsletter-form {
        flex-direction: column;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-brand .logo {
        justify-content: center;
    }

    .footer-bottom {
        flex-direction: column;
        gap: var(--space-md);
    }

    .chart-bars {
        height: 200px;
    }

    .chart-bar {
        width: 35px;
    }

    .bar-value {
        font-size: 0.75rem;
        top: -25px;
    }
}

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

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-desc {
        font-size: 1rem;
    }

    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

    .news-filter {
        gap: var(--space-xs);
    }

    .filter-btn {
        padding: 0.375rem 0.75rem;
        font-size: 0.75rem;
    }
}

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

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

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

/* Intersection Observer Animation Classes */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

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

/* Print Styles */
@media print {
    .header,
    .hero-scroll,
    .news-ticker,
    .newsletter-section,
    .back-to-top,
    .mobile-menu-btn {
        display: none !important;
    }

    .hero {
        min-height: auto;
        padding: var(--space-lg);
    }

    .hero-bg {
        background: var(--gray-100);
    }

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