/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    --primary-bg: #0a0a0f;
    --secondary-bg: #12121a;
    --card-bg: #1a1a25;
    --border-color: rgba(255, 255, 255, 0.08);

    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);

    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-accent: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);

    --intent-informative: #3b82f6;
    --intent-denouncing: #ef4444;
    --intent-questioning: #f59e0b;
    --intent-positive: #10b981;

    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-heading: 'Space Grotesk', sans-serif;

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;

    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

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

/* ===================================
   Typography
   =================================== */
h1,
h2,
h3,
h4 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
}

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

h2 {
    font-size: clamp(1.8rem, 3vw, 2.5rem);
}

h3 {
    font-size: clamp(1.2rem, 2vw, 1.5rem);
}

p {
    color: var(--text-secondary);
}

.lead {
    font-size: 1.125rem;
    line-height: 1.7;
}

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

/* ===================================
   Layout
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(102, 126, 234, 0.15);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: 20px;
    font-size: 0.875rem;
    color: #667eea;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.section-description {
    max-width: 600px;
    margin: -40px auto 50px;
    text-align: center;
    color: var(--text-secondary);
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-menu a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

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

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 40px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 120px 24px 80px;
}

.hero-background {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.grid-pattern {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(102, 126, 234, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(102, 126, 234, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 20%, transparent 70%);
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 900px;
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: 30px;
    font-size: 0.875rem;
    color: #667eea;
    margin-bottom: 24px;
}

.hero-title {
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 24px;
}

.hero-authors {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 48px;
}

.hero-authors strong {
    color: var(--text-secondary);
    font-weight: 500;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    text-align: center;
}

.stat-value {
    display: block;
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===================================
   About Section
   =================================== */
.about {
    background: var(--secondary-bg);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    margin-bottom: 20px;
}

.intent-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.intent-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    transition: var(--transition);
}

.intent-card:hover {
    transform: translateY(-4px);
}

.intent-icon {
    font-size: 2rem;
    margin-bottom: 12px;
}

.intent-card h3 {
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.intent-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.intent-card.informative {
    border-top: 3px solid var(--intent-informative);
}

.intent-card.denouncing {
    border-top: 3px solid var(--intent-denouncing);
}

.intent-card.questioning {
    border-top: 3px solid var(--intent-questioning);
}

.intent-card.positive {
    border-top: 3px solid var(--intent-positive);
}

/* ===================================
   Methodology Section
   =================================== */
.architecture-diagram {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    margin-bottom: 60px;
    overflow-x: auto;
}

.arch-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    min-width: max-content;
}

.arch-node {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
    min-width: 140px;
}

.node-icon {
    font-size: 1.5rem;
    margin-bottom: 8px;
}

.arch-node h4 {
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.arch-node p {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.arch-arrow {
    font-size: 1.5rem;
    color: var(--text-muted);
}

.encoder-node {
    border-color: var(--intent-informative);
}

.fusion-node {
    border-color: #a855f7;
}

.decoder-node {
    border-color: var(--intent-positive);
}

.subsection-title {
    text-align: center;
    margin-bottom: 32px;
}

.fusion-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.fusion-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 28px;
    transition: var(--transition);
}

.fusion-card:hover {
    transform: translateY(-4px);
    border-color: rgba(102, 126, 234, 0.3);
}

.fusion-card.featured {
    border-color: rgba(102, 126, 234, 0.5);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
}

.fusion-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.fusion-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-weight: bold;
}

.fusion-header.linear .fusion-icon {
    background: rgba(59, 130, 246, 0.2);
    color: var(--intent-informative);
}

.fusion-header.shared .fusion-icon {
    background: rgba(168, 85, 247, 0.2);
    color: #a855f7;
}

.fusion-header.cross .fusion-icon {
    background: rgba(16, 185, 129, 0.2);
    color: var(--intent-positive);
}

.fusion-header h4 {
    font-size: 1rem;
}

.badge {
    padding: 4px 10px;
    background: var(--gradient-primary);
    border-radius: 12px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.fusion-card p {
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.fusion-metrics {
    display: flex;
    gap: 16px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ===================================
   Results Section
   =================================== */
.results {
    background: var(--secondary-bg);
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
}

.results-table-container {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 28px;
}

.results-table-container h3 {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.results-table {
    width: 100%;
    border-collapse: collapse;
}

.results-table th,
.results-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.results-table th {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.results-table td {
    font-size: 0.9rem;
}

.results-table tr.highlight {
    background: rgba(102, 126, 234, 0.1);
}

.results-table tr.highlight td {
    color: var(--text-primary);
}

.results-table tr.baseline td {
    color: var(--text-muted);
}

.results-legend {
    text-align: center;
    margin-top: 32px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ===================================
   Examples Section
   =================================== */
.examples-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

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

.example-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.example-hate,
.example-counter {
    padding: 24px;
}

.example-hate {
    background: rgba(239, 68, 68, 0.05);
    border-bottom: 1px solid var(--border-color);
}

.label {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
}

.hate-label {
    background: rgba(239, 68, 68, 0.2);
    color: #f87171;
}

.counter-label {
    background: rgba(16, 185, 129, 0.2);
    color: #34d399;
}

.example-hate p,
.example-counter p {
    color: var(--text-primary);
    font-size: 0.95rem;
}

.example-counter.informative {
    border-left: 3px solid var(--intent-informative);
}

.example-counter.denouncing {
    border-left: 3px solid var(--intent-denouncing);
}

.example-counter.questioning {
    border-left: 3px solid var(--intent-questioning);
}

.example-counter.positive {
    border-left: 3px solid var(--intent-positive);
}

/* ===================================
   Resources Section
   =================================== */
.resources {
    background: var(--secondary-bg);
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.resource-card {
    display: block;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-decoration: none;
    transition: var(--transition);
}

.resource-card:hover {
    transform: translateY(-4px);
    border-color: rgba(102, 126, 234, 0.3);
}

.resource-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.resource-card h3 {
    margin-bottom: 8px;
    color: var(--text-primary);
}

.resource-card p {
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.resource-link {
    color: #667eea;
    font-size: 0.9rem;
    font-weight: 500;
}

.resource-card.dataset {
    grid-column: span 2;
}

.dataset-stats {
    display: flex;
    gap: 24px;
    margin-top: 16px;
}

.dataset-stats span {
    padding: 8px 16px;
    background: rgba(102, 126, 234, 0.1);
    border-radius: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--primary-bg);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-brand h3 {
    font-size: 1.5rem;
    margin-bottom: 8px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.footer-brand p {
    color: var(--text-muted);
}

.footer-links h4 {
    font-size: 0.9rem;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.footer-links a {
    display: block;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    margin-bottom: 8px;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .fusion-cards {
        grid-template-columns: 1fr;
    }

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

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

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

    .resource-card.dataset {
        grid-column: span 1;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .hero-stats {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }

    .stat-card {
        padding: 16px;
    }

    .stat-value {
        font-size: 1.5rem;
    }

    .arch-flow {
        flex-direction: column;
    }

    .arch-arrow {
        transform: rotate(90deg);
    }

    .intent-cards {
        grid-template-columns: 1fr;
    }

    .section {
        padding: 60px 0;
    }

    .dataset-stats {
        flex-wrap: wrap;
    }
}

@media (max-width: 480px) {
    .hero-stats {
        grid-template-columns: 1fr;
    }

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

    .btn {
        width: 100%;
        justify-content: center;
    }
}