/* ============================================
   LineSight — Design System & Landing Page CSS
   ============================================ */

/* ---- CSS Variables ---- */
:root {
    /* Brand Colors (Monochrome Overrides) */
    --purple-50: #f8f9fa;
    --purple-100: #e9ecef;
    --purple-200: #dee2e6;
    --purple-300: #ced4da;
    --purple-400: #adb5bd;
    --purple-500: #6c757d;
    --purple-600: #495057;
    --purple-700: #343a40;
    --purple-800: #212529;
    --purple-900: #111111;

    /* Accent Palette (Monochrome Overrides) */
    --accent-primary: #111111;
    --accent-blue: #333333;
    --accent-teal: #444444;
    --accent-amber: #555555;
    --accent-rose: #666666;
    --accent-green: #222222;

    /* Backgrounds */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f1f3f5;
    --bg-card: #ffffff;
    --bg-card-hover: #f8f9fa;
    --bg-elevated: #ffffff;
    --bg-surface: rgba(0, 0, 0, 0.03);

    /* Text */
    --text-primary: #212529;
    --text-secondary: #495057;
    --text-tertiary: #868e96;
    --text-inverse: #ffffff;

    /* Borders */
    --border-subtle: rgba(0, 0, 0, 0.06);
    --border-default: rgba(0, 0, 0, 0.10);
    --border-hover: rgba(0, 0, 0, 0.15);
    --border-accent: rgba(0, 0, 0, 0.15);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 40px rgba(0, 0, 0, 0.05);

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 96px;

    /* Typography */
    --font-sans: 'Century Gothic', 'CenturyGothic', AppleGothic, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Radii */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-default: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout */
    --max-width: 1200px;
    --nav-height: 64px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

code {
    font-family: var(--font-mono);
    font-size: 0.85em;
    background: rgba(0, 0, 0, 0.05);
    color: #333333;
    padding: 2px 6px;
    border-radius: 4px;
}

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

/* ---- Scrollbar ---- */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--border-default);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--border-hover);
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    z-index: 1000;
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border-subtle);
    transition: background var(--transition-default), box-shadow var(--transition-default);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.92);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-shrink: 0;
}

.logo-icon {
    display: flex;
    align-items: center;
}

.logo-text {
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.logo-version {
    font-size: 0.7rem;
    font-weight: 500;
    color: #666666;
    background: rgba(0, 0, 0, 0.06);
    padding: 2px 7px;
    border-radius: 20px;
    letter-spacing: 0.02em;
}

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

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-link:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

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

.nav-github {
    display: flex;
    align-items: center;
    color: var(--text-secondary);
    padding: 6px;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-github:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-menu-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--text-secondary);
    border-radius: 2px;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--nav-height);
    overflow: hidden;
}

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

.hero-grid-line {
    position: absolute;
    background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.04), transparent);
    width: 1px;
}

.hero-grid-line-1 { left: 20%; top: 0; height: 100%; }
.hero-grid-line-2 { left: 50%; top: 0; height: 100%; }
.hero-grid-line-3 { left: 80%; top: 0; height: 100%; }

.hero-orb {
    display: none;
}

.hero-orb-1, .hero-orb-2, .hero-orb-3 {
    display: none;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--space-3xl) var(--space-lg);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.15);
    padding: 6px 14px;
    border-radius: 20px;
    margin-bottom: var(--space-lg);
    letter-spacing: 0.02em;
}

.badge-dot {
    width: 6px;
    height: 6px;
    background: var(--accent-green);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.75rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

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

.hero-subtitle {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    max-width: 540px;
    margin-bottom: var(--space-xl);
}

.hero-subtitle em {
    font-style: normal;
    color: var(--text-primary);
    font-weight: 500;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-2xl);
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition-default);
    white-space: nowrap;
}

.btn-primary {
    background: var(--accent-primary);
    color: white;
    box-shadow: 0 4px 14px rgba(26, 115, 232, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(26, 115, 232, 0.45);
}

.btn-secondary {
    background: var(--bg-elevated);
    color: var(--text-primary);
    border: 1px solid var(--border-default);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 500;
}

.btn-secondary:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-hover);
}

/* Stats */
.hero-stats {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.stat {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 0.78rem;
    color: var(--text-tertiary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.stat-divider {
    width: 1px;
    height: 36px;
    background: var(--border-default);
}

/* Code Window */
.hero-visual {
    position: relative;
}

.code-window {
    background: #000000;
    border: 1px solid #2a2a2a;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-slow), box-shadow var(--transition-slow);
}

.code-window:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.code-window-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: 12px 16px;
    background: #1A1A1A;
    border-bottom: 1px solid #2a2a2a;
}

.code-window-dots {
    display: flex;
    gap: 6px;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.dot-red { background: #333333; }
.dot-yellow { background: #555555; }
.dot-green { background: #777777; }

.code-window-title {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

.code-window-body {
    padding: 20px 24px;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    line-height: 1.8;
    overflow-x: auto;
    color: #FFFFFF;
}

.code-window-body code {
    background: none;
    padding: 0;
    font-size: inherit;
    color: inherit;
}

/* Syntax highlighting */
.code-keyword { color: #FFFF00; font-weight: bold; }
.code-module { color: #FFFFFF; }
.code-class { color: #FFFFFF; font-weight: bold; }
.code-var { color: #FFFFFF; }
.code-param { color: #FFFFFF; }
.code-number { color: #FFFFFF; }
.code-bool { color: #FFFFFF; }
.code-method { color: #FFFFFF; }
.code-comment { color: #666666; font-style: italic; }
.code-output { color: #888888; opacity: 0.9; }

/* ============================================
   SECTIONS — Shared
   ============================================ */
.section {
    padding: var(--space-4xl) 0;
    position: relative;
}

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

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
    background: rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.1);
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: var(--space-md);
}

.section-title {
    font-size: clamp(2rem, 3.5vw, 2.75rem);
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 640px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ============================================
   TUTORIALS SECTION
   ============================================ */
.tutorials-section {
    background: var(--bg-primary);
}

.tutorial-group {
    margin-bottom: var(--space-3xl);
}

.tutorial-group:last-child {
    margin-bottom: 0;
}

.group-header {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--border-subtle);
}

.group-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    flex-shrink: 0;
}

.group-icon-beginner {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.group-icon-expert {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.group-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.group-desc {
    font-size: 0.88rem;
    color: var(--text-secondary);
}

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

.tutorial-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-default);
    display: flex;
    flex-direction: column;
}

.tutorial-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card-accent {
    height: 3px;
    width: 100%;
}

.card-accent-purple { background: var(--accent-primary); }
.card-accent-blue { background: var(--accent-primary); }
.card-accent-teal { background: var(--accent-primary); }
.card-accent-amber { background: var(--accent-primary); }
.card-accent-rose { background: var(--accent-primary); }
.card-accent-green { background: var(--accent-primary); }

.card-body {
    padding: var(--space-xl) var(--space-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-tag {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-tertiary);
    margin-bottom: var(--space-sm);
}

.card-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    letter-spacing: -0.01em;
}

.card-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
    flex: 1;
}

.card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-subtle);
}

.card-model {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--text-tertiary);
}

.card-arrow {
    font-size: 1.1rem;
    color: var(--text-secondary);
    transition: transform var(--transition-fast);
}

.tutorial-card:hover .card-arrow {
    transform: translateX(4px);
}

/* ============================================
   MODELS SECTION
   ============================================ */
.models-section {
    background: var(--bg-secondary);
}

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

.model-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: var(--space-xl) var(--space-lg);
    transition: all var(--transition-default);
}

.model-card:hover {
    border-color: var(--border-accent);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.model-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    margin-bottom: var(--space-md);
}

.model-icon-linear {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.model-icon-multiple {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.model-icon-ridge {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.model-icon-lasso {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.model-icon-elasticnet {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.model-icon-logistic {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.model-name {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.model-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-md);
}

.model-algo {
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-secondary);
    background: rgba(0, 0, 0, 0.05);
    padding: 4px 10px;
    border-radius: 12px;
    display: inline-block;
}

/* ============================================
   FEATURES / ARCHITECTURE SECTION
   ============================================ */
.features-section {
    background: var(--bg-primary);
}

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

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl) var(--space-xl);
    text-align: center;
    transition: all var(--transition-default);
}

.feature-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-lg);
}

.feature-icon-engine {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.feature-icon-explain {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.feature-icon-viz {
    background: rgba(0, 0, 0, 0.05);
    color: #111111;
}

.feature-name {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.feature-desc {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   INSTALL SECTION
   ============================================ */
.install-section {
    background: var(--bg-secondary);
}

.install-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-xl);
    padding: var(--space-3xl);
    position: relative;
    overflow: hidden;
}

.install-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: none;
    border-radius: 50%;
    pointer-events: none;
}

.install-content {
    position: relative;
    z-index: 1;
}

.install-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    letter-spacing: -0.02em;
}

.install-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
}

.install-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.install-step {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    min-width: 28px;
    background: rgba(0, 0, 0, 0.08);
    color: var(--text-primary);
    border-radius: 50%;
    font-size: 0.8rem;
    font-weight: 700;
    margin-top: 2px;
}

.step-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
    display: block;
}

.install-code {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    background: var(--bg-primary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: 12px 16px;
}

.install-code code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-primary);
    background: none;
    padding: 0;
    flex: 1;
    white-space: nowrap;
    overflow-x: auto;
}

.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: none;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--text-tertiary);
    cursor: pointer;
    flex-shrink: 0;
    transition: all var(--transition-fast);
}

.copy-btn:hover {
    color: var(--text-primary);
    border-color: var(--border-hover);
    background: rgba(255, 255, 255, 0.05);
}

.copy-btn.copied {
    color: #000000;
    border-color: #000000;
}

.install-reqs {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.req-badge {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-subtle);
    padding: 5px 12px;
    border-radius: var(--radius-sm);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-subtle);
    padding: var(--space-3xl) 0 var(--space-xl);
}

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

.footer-top {
    display: flex;
    justify-content: space-between;
    gap: var(--space-3xl);
    margin-bottom: var(--space-2xl);
    padding-bottom: var(--space-2xl);
    border-bottom: 1px solid var(--border-subtle);
}

.footer-brand {
    max-width: 280px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.footer-tagline {
    font-size: 0.85rem;
    color: var(--text-tertiary);
    line-height: 1.6;
}

.footer-links-group {
    display: flex;
    gap: var(--space-3xl);
}

.footer-col {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-col-title {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-tertiary);
    margin-bottom: var(--space-xs);
}

.footer-link {
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

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

.footer-copy {
    font-size: 0.78rem;
    color: var(--text-tertiary);
}

/* ============================================
   SCROLL ANIMATIONS
   ============================================ */
.fade-in-up {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
        text-align: center;
    }

    .hero-content {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }

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

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

    .hero-visual {
        max-width: 560px;
        margin: 0 auto;
    }

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.97);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--space-lg);
        gap: var(--space-xs);
        border-bottom: 1px solid var(--border-subtle);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-link {
        width: 100%;
        padding: 12px 16px;
    }

    .nav-menu-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2.2rem;
    }

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

    .footer-top {
        flex-direction: column;
    }

    .footer-brand {
        max-width: 100%;
    }

    .footer-links-group {
        flex-wrap: wrap;
        gap: var(--space-xl);
    }

    .install-card {
        padding: var(--space-xl);
    }

    .install-code code {
        font-size: 0.75rem;
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

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

@media (max-width: 480px) {
    .hero-stats {
        gap: var(--space-md);
    }

    .stat-value {
        font-size: 1.2rem;
    }

    .hero-badge {
        font-size: 0.72rem;
    }
}