/* ============================================
   ByteDance Seed - Combined Projects Page
   Light Theme with Horizontal Scroll
   ============================================ */

/* CSS Variables - Pure White Background Version */
:root {
    /* Primary palette - All Pure White */
    --color-bg-dark: #ffffff;
    --color-bg-medium: #ffffff;
    --color-bg-light: #ffffff;
    --color-bg-card: #ffffff;
    
    /* SeedFold colors */
    --color-seedfold: #2563eb;
    --color-seedfold-dim: rgba(37, 99, 235, 0.1);
    --color-seedfold-secondary: #0891b2;
    
    /* SeedProteo colors */
    --color-seedproteo: #7c3aed;
    --color-seedproteo-dim: rgba(124, 58, 237, 0.1);
    --color-seedproteo-secondary: #ec4899;
    
    /* Text colors */
    --color-text-primary: #0f172a;
    --color-text-secondary: #475569;
    --color-text-muted: #64748b;
    
    /* Typography */
    --font-display: 'Outfit', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Effects */
    --border-subtle: 1px solid rgba(0, 0, 0, 0.08);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.08);
}

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

html {
    scroll-behavior: smooth;
}

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

/* ============================================
   Top Navigation
   ============================================ */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: var(--border-subtle);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--color-text-primary);
    text-decoration: none;
}

.logo-image {
    height: 56px;
    width: auto;
    display: block;
}

.logo-icon {
    font-size: 1.6rem;
}

.logo-text {
    background: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Project Tabs */
.project-tabs {
    display: flex;
    gap: 8px;
    padding: 4px;
    background: var(--color-bg-light);
    border-radius: 12px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.tab-btn {
    padding: 10px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    font-family: var(--font-display);
    color: var(--color-text-secondary);
    background: transparent;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    color: var(--color-text-primary);
}

.tab-btn.active {
    color: #ffffff;
    background: var(--color-seedfold);
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.tab-btn.active[data-project="seedproteo"] {
    background: var(--color-seedproteo);
    box-shadow: 0 2px 8px rgba(124, 58, 237, 0.3);
}

.nav-links {
    display: flex;
    gap: 16px;
}

.nav-btn {
    padding: 10px 20px;
    font-size: 0.9rem;
    font-weight: 600;
    color: #ffffff;
    background: var(--color-text-primary);
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.nav-btn:hover {
    background: var(--color-seedfold);
}

.nav-btn.try-btn {
    background: var(--color-seedfold);
}

.nav-btn.disabled {
    background: #94a3b8;
    cursor: not-allowed;
    opacity: 0.6;
}

.nav-btn.disabled:hover {
    background: #94a3b8;
    transform: none;
}

.nav-btn .external-icon {
    opacity: 0.9;
    transition: transform 0.3s ease;
}

.nav-btn:hover .external-icon {
    transform: translate(2px, -2px);
}

/* ============================================
   Horizontal Scroll Container
   ============================================ */
.projects-wrapper {
    width: 100%;
    overflow-x: hidden;
    margin-top: 72px;
}

.projects-container {
    display: flex;
    width: 200vw;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.project-section {
    width: 100vw;
    min-height: calc(100vh - 72px);
    flex-shrink: 0;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    min-height: auto;
    padding: 80px 32px 60px;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    background: #ffffff;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(0,0,0,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,0,0,0.02) 1px, transparent 1px);
    background-size: 60px 60px;
}

.helix {
    position: absolute;
    width: 350px;
    height: 350px;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.25;
    display: none; /* Hidden for pure white background */
}

.helix-1 {
    top: 10%;
    left: -5%;
    background: var(--color-seedfold);
}

.helix-2 {
    bottom: 20%;
    right: -5%;
    background: var(--color-seedfold-secondary);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: var(--color-seedfold-dim);
    border: 1px solid rgba(37, 99, 235, 0.2);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-seedfold);
    margin-bottom: 20px;
}

.hero-title {
    margin-bottom: 20px;
}

.title-main {
    display: block;
    font-size: clamp(2.5rem, 7vw, 4.5rem);
    font-weight: 700;
    background: linear-gradient(135deg, #2563eb 0%, #0891b2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -1px;
}

.title-sub {
    display: block;
    font-size: clamp(1rem, 2.5vw, 1.5rem);
    font-weight: 400;
    color: var(--color-text-secondary);
    margin-top: 8px;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    max-width: 900px;
    margin: 0 auto 32px;
    line-height: 1.7;
}

.hero-description strong {
    color: var(--color-seedfold);
    font-weight: 600;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 32px;
    flex-wrap: wrap;
}

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

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    font-family: var(--font-mono);
    color: var(--color-text-primary);
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-top: 4px;
}

.hero-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    margin-bottom: 40px;
}

.hero-actions-main {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.hero-actions-social {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 10px;
    text-decoration: none;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
}

.btn svg {
    opacity: 0.9;
    transition: transform 0.3s ease;
}

.btn:hover svg {
    transform: translate(2px, -2px);
}

.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 10px;
    background: var(--color-bg-light);
    border: var(--border-subtle);
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
}

.btn-icon svg {
    width: 24px;
    height: 24px;
    color: var(--color-text-secondary);
    transition: all 0.2s ease;
}

.btn-icon:hover {
    background: var(--color-bg-medium);
    border-color: var(--color-seedfold);
    transform: translateY(-2px);
}

.btn-icon:hover svg {
    color: var(--color-seedfold);
}

.btn-icon:active {
    transform: translateY(0);
}

/* Tooltip effect */
.btn-icon::after {
    content: attr(title);
    position: absolute;
    bottom: -40px;
    left: 50%;
    transform: translateX(-50%) scale(0.8);
    padding: 6px 12px;
    background: var(--color-text-primary);
    color: var(--color-bg-card);
    font-size: 0.75rem;
    border-radius: 6px;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: all 0.2s ease;
}

.btn-icon:hover::after {
    opacity: 1;
    transform: translateX(-50%) scale(1);
}

.btn-primary {
    background: var(--color-seedfold);
    color: #ffffff;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text-primary);
    border: 2px solid rgba(0, 0, 0, 0.15);
}

.btn-secondary:hover {
    border-color: var(--color-seedfold);
    color: var(--color-seedfold);
}

.hero-figure {
    position: relative;
    z-index: 1;
    max-width: 900px;
    margin: 0 auto;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-card);
    border: var(--border-subtle);
    background: #ffffff;
}

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

/* ============================================
   Sections
   ============================================ */
.section {
    padding: 80px 0;
}

.section.contributions {
    background: var(--color-bg-medium);
}

.section.results {
    background: var(--color-bg-dark);
}

.section.method {
    background: var(--color-bg-medium);
}

.section.citation-section {
    background: var(--color-bg-light);
    padding: 60px 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
}

.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: var(--color-seedfold-dim);
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-seedfold);
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    color: var(--color-text-primary);
    margin-bottom: 12px;
}

.section-desc {
    font-size: 1rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   Contributions Grid
   ============================================ */
.contributions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.contribution-card {
    position: relative;
    padding: 32px;
    background: var(--color-bg-card);
    border-radius: 16px;
    border: var(--border-subtle);
    box-shadow: var(--shadow-card);
    transition: all 0.3s ease;
}

.contribution-card::before {
    content: attr(data-index);
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 3rem;
    font-weight: 800;
    font-family: var(--font-mono);
    color: rgba(0, 0, 0, 0.03);
    line-height: 1;
}

.contribution-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
}

.card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-seedfold-dim);
    border-radius: 12px;
    margin-bottom: 20px;
}

.card-icon svg {
    width: 24px;
    height: 24px;
    color: var(--color-seedfold);
}

.contribution-card h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
    color: var(--color-text-primary);
}

.contribution-card p {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 16px;
}

.card-highlights {
    list-style: none;
}

.card-highlights li {
    position: relative;
    padding-left: 16px;
    margin-bottom: 6px;
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.card-highlights li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--color-seedfold);
}

/* ============================================
   Results Table
   ============================================ */
.results-table-wrapper {
    overflow-x: auto;
    margin-bottom: 32px;
    border-radius: 12px;
    border: var(--border-subtle);
    background: var(--color-bg-card);
    box-shadow: var(--shadow-card);
}

.results-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.results-table th,
.results-table td {
    padding: 14px 16px;
    text-align: center;
    border-bottom: var(--border-subtle);
}

.results-table th {
    background: var(--color-bg-light);
    font-weight: 600;
    color: var(--color-text-primary);
}

.results-table th .metric {
    display: block;
    font-size: 0.7rem;
    font-weight: 400;
    color: var(--color-text-muted);
    margin-top: 2px;
}

.results-table td {
    color: var(--color-text-secondary);
}

.results-table .model-name {
    text-align: left;
    font-weight: 500;
    color: var(--color-text-primary);
}

.results-table .model-name.ours {
    color: var(--color-seedfold);
    font-weight: 600;
}

.results-table .best {
    color: var(--color-seedfold);
    font-weight: 700;
}

.results-table .second {
    color: var(--color-seedfold-secondary);
    font-weight: 600;
}

.results-table .highlight-row {
    background: rgba(37, 99, 235, 0.05);
}

.results-table .category-row td {
    padding: 10px 16px;
    font-size: 0.85rem;
}

/* Novelty Table specific styles */
.novelty-table {
    font-size: 0.85rem;
}

.novelty-table th,
.novelty-table td {
    padding: 12px 10px;
}

.novelty-table .best {
    color: #059669;
    font-weight: 700;
}

.novelty-table .second {
    color: #0891b2;
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 2px;
}

/* Performance Highlights */
.performance-highlights {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 24px;
    background: var(--color-bg-card);
    border-radius: 10px;
    border: var(--border-subtle);
    box-shadow: var(--shadow-card);
}

.highlight-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-seedfold-dim);
    border-radius: 8px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-seedfold);
}

.highlight-content {
    display: flex;
    flex-direction: column;
}

.highlight-value {
    font-size: 1.2rem;
    font-weight: 700;
    font-family: var(--font-mono);
    color: var(--color-seedfold);
}

.highlight-label {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

/* ============================================
   Method Grid
   ============================================ */
.method-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
    margin-bottom: 60px;
}

.method-grid.reverse {
    direction: rtl;
}

.method-grid.reverse > * {
    direction: ltr;
}

.method-figure {
    border-radius: 12px;
    overflow: hidden;
    border: var(--border-subtle);
    background: var(--color-bg-card);
    box-shadow: var(--shadow-card);
}

.method-figure.large {
    grid-column: span 1;
}

.method-figure img {
    width: 100%;
    height: auto;
    display: block;
}

.method-content h3 {
    font-size: 1.4rem;
    margin-bottom: 12px;
}

.method-content p {
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

.method-content ul {
    list-style: none;
}

.method-content li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 10px;
    color: var(--color-text-secondary);
}

.method-content li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-seedfold);
}

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

/* Scaling Stats */
.scaling-stats {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 16px;
}

.scaling-item {
    display: grid;
    grid-template-columns: 100px 1fr 60px;
    align-items: center;
    gap: 12px;
}

.scaling-label {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

.scaling-bar {
    height: 8px;
    background: var(--color-bg-light);
    border-radius: 4px;
    overflow: hidden;
    position: relative;
}

.scaling-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: var(--width);
    background: linear-gradient(135deg, #2563eb 0%, #0891b2 100%);
    border-radius: 4px;
}

.scaling-item.highlight .scaling-label {
    color: var(--color-seedfold);
    font-weight: 600;
}

.scaling-value {
    font-size: 0.85rem;
    font-family: var(--font-mono);
    color: var(--color-text-muted);
    text-align: right;
}

/* Result Figure */
.result-figure {
    max-width: 900px;
    margin: 0 auto;
    border-radius: 12px;
    overflow: hidden;
    border: var(--border-subtle);
    background: var(--color-bg-card);
    box-shadow: var(--shadow-card);
}

.result-figure.large-figure {
    max-width: 1100px;
}

.result-figure img {
    width: 100%;
    height: auto;
    display: block;
}

.figure-caption {
    padding: 16px 24px;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    text-align: center;
    background: var(--color-bg-light);
}

/* ============================================
   Method Section - Architecture
   ============================================ */
.method-architecture {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 48px;
    align-items: center;
    margin-bottom: 80px;
}

.arch-figure {
    border-radius: 16px;
    overflow: hidden;
    border: var(--border-subtle);
    background: var(--color-bg-card);
    box-shadow: var(--shadow-card);
}

.arch-figure img {
    width: 100%;
    height: auto;
    display: block;
}

.arch-description h3 {
    font-size: 1.6rem;
    margin-bottom: 16px;
}

.arch-description p {
    color: var(--color-text-secondary);
    margin-bottom: 24px;
}

.arch-description ul {
    list-style: none;
}

.arch-description li {
    position: relative;
    padding-left: 24px;
    margin-bottom: 16px;
    color: var(--color-text-secondary);
}

.arch-description li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-seedfold);
}

.arch-description li strong {
    color: var(--color-text-primary);
}

/* Method Section - Scaling */
.method-scaling {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
    margin-bottom: 80px;
}

.scaling-content h3 {
    font-size: 1.6rem;
    margin-bottom: 16px;
}

.scaling-content > p {
    color: var(--color-text-secondary);
    margin-bottom: 32px;
}

.scaling-stats {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.scaling-item {
    display: grid;
    grid-template-columns: 160px 1fr 120px;
    align-items: center;
    gap: 20px;
}

.scaling-label {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.scaling-bar {
    height: 10px;
    background: var(--color-bg-light);
    border-radius: 5px;
    overflow: hidden;
    position: relative;
}

.scaling-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: var(--width);
    background: var(--gradient-seedfold-accent);
    border-radius: 5px;
    transition: width 0.6s ease;
}

.scaling-item.highlight .scaling-label {
    color: var(--color-seedfold);
    font-weight: 600;
}

.scaling-value {
    font-size: 0.9rem;
    font-family: var(--font-mono);
    color: var(--color-text-muted);
    text-align: right;
}

.scaling-figure {
    border-radius: 16px;
    overflow: hidden;
    border: var(--border-subtle);
    background: var(--color-bg-card);
    box-shadow: var(--shadow-card);
}

.scaling-figure img {
    width: 100%;
    height: auto;
    display: block;
}

/* Method Section - Linear Attention */
.method-attention {
    display: grid;
    grid-template-columns: 0.85fr 1.15fr;
    gap: 48px;
    align-items: center;
}

.attention-figure {
    max-width: 420px;
    border-radius: 12px;
    overflow: hidden;
    border: var(--border-subtle);
    background: var(--color-bg-card);
    box-shadow: var(--shadow-card);
}

.attention-figure img {
    width: 100%;
    height: auto;
    display: block;
}

.attention-content h3 {
    font-size: 1.6rem;
    margin-bottom: 16px;
}

.attention-content > p {
    color: var(--color-text-secondary);
    margin-bottom: 24px;
    line-height: 1.7;
}

.attention-variants {
    display: flex;
    gap: 16px;
}

.variant {
    flex: 1;
    padding: 16px;
    background: var(--color-bg-light);
    border-radius: 10px;
    border: var(--border-subtle);
}

.variant h4 {
    font-size: 0.9rem;
    margin-bottom: 8px;
    color: var(--color-seedfold);
}

.variant code {
    display: inline-block;
    padding: 4px 10px;
    background: var(--color-bg-card);
    border-radius: 6px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--color-text-primary);
    border: var(--border-subtle);
}

.variant p {
    margin-top: 8px;
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* ============================================
   Team Section
   ============================================ */
.team {
    padding: 80px 0;
    background: var(--color-bg-dark);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-bottom: 48px;
}

.team-category h3 {
    font-size: 1rem;
    color: var(--color-text-muted);
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.team-members {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.member {
    padding: 10px 20px;
    background: var(--color-bg-light);
    border-radius: 8px;
    font-size: 0.95rem;
    color: var(--color-text-primary);
    border: var(--border-subtle);
}

.member.lead {
    background: var(--color-seedfold-dim);
    border-color: rgba(37, 99, 235, 0.3);
}

.team-note {
    margin-top: 12px;
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.affiliation {
    text-align: center;
    padding-top: 40px;
    border-top: var(--border-subtle);
}

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

/* ============================================
   Citation
   ============================================ */
.citation-box {
    max-width: 700px;
    margin: 0 auto;
    padding: 24px;
    background: var(--color-bg-card);
    border-radius: 12px;
    border: var(--border-subtle);
    box-shadow: var(--shadow-card);
    overflow-x: auto;
}

.citation-box pre {
    margin: 0;
}

.citation-box code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    padding: 40px 0;
    background: var(--color-bg-light);
    border-top: var(--border-subtle);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.footer-logo-image {
    height: 40px;
    width: auto;
    display: block;
}

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

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
    .method-grid {
        grid-template-columns: 1fr;
    }
    
    .method-grid.reverse {
        direction: ltr;
    }
    
    .method-architecture {
        grid-template-columns: 1fr;
    }
    
    .method-scaling {
        grid-template-columns: 1fr;
    }
    
    .method-attention {
        grid-template-columns: 1fr;
    }
    
    .attention-figure {
        max-width: 100%;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .project-tabs {
        display: none;
    }
    
    .hero {
        padding: 60px 24px 40px;
    }
    
    .hero-stats {
        gap: 24px;
    }
    
    .stat-value {
        font-size: 1.6rem;
    }
    
    .contributions-grid {
        grid-template-columns: 1fr;
    }
    
    .performance-highlights {
        flex-direction: column;
        align-items: center;
    }
    
    .scaling-item {
        grid-template-columns: 1fr;
        gap: 4px;
    }
    
    .attention-variants {
        flex-direction: column;
    }
    
    .hero-actions-main {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-actions-main .btn {
        width: 100%;
        max-width: 320px;
    }
    
    .btn-icon::after {
        display: none;
    }
}

/* ============================================
   WeChat Modal
   ============================================ */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    z-index: 10000;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.2s ease;
}

.modal.active {
    display: flex;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.modal-content {
    background: var(--color-bg-card);
    border-radius: 20px;
    padding: 40px;
    max-width: 450px;
    width: 90%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    border: var(--border-subtle);
    position: relative;
    animation: slideUp 0.3s ease;
}

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

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: var(--color-bg-light);
    border: none;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    color: var(--color-text-muted);
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    background: var(--color-bg-medium);
    color: var(--color-text-primary);
    transform: rotate(90deg);
}

.modal-title {
    font-size: 1.8rem;
    margin-bottom: 12px;
    color: var(--color-text-primary);
    text-align: center;
}

.modal-desc {
    color: var(--color-text-secondary);
    text-align: center;
    margin-bottom: 32px;
}

.qr-container {
    display: flex;
    justify-content: center;
    margin-bottom: 24px;
    padding: 20px;
    background: #ffffff;
    border-radius: 16px;
}

.qr-container img {
    width: 250px;
    height: 250px;
    display: block;
}

.modal-note {
    color: var(--color-text-muted);
    font-size: 0.85rem;
    text-align: center;
    line-height: 1.6;
}