/*
 * Riverova Design System v2.0
 * AI-Native Education Operating System
 * Pure CSS — No Framework Dependencies
 * All values driven by CSS Custom Properties
 */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Sora:wght@300;400;500;600;700;800&display=swap');

/* ==========================================================================
   1. DESIGN TOKENS
   ========================================================================== */

:root {
    /* Brand Colors */
    --brand-primary:        #f97316;
    --brand-primary-dark:   #c2410c;
    --brand-primary-light:  #fff7ed;
    --brand-accent:         #6366f1;
    --brand-accent-dark:    #4338ca;
    --brand-accent-light:   #eef2ff;

    /* Semantic Surface Colors */
    --surface-page:         #f8fafc;
    --surface-card:         #ffffff;
    --surface-elevated:     #ffffff;
    --surface-subtle:       #f1f5f9;
    --surface-dark:         #0f172a;
    --surface-dark-muted:   #1e293b;

    /* Text Colors */
    --text-primary:         #0f172a;
    --text-secondary:       #334155;
    --text-muted:           #64748b;
    --text-faint:           #94a3b8;
    --text-inverse:         #ffffff;
    --text-accent:          #f97316;

    /* Border Colors */
    --border-default:       rgba(15, 23, 42, 0.08);
    --border-strong:        rgba(15, 23, 42, 0.15);
    --border-subtle:        rgba(15, 23, 42, 0.05);

    /* Status Colors */
    --status-success:       #16a34a;
    --status-success-bg:    #dcfce7;
    --status-warning:       #d97706;
    --status-warning-bg:    #fef3c7;
    --status-info:          #2563eb;
    --status-info-bg:       #dbeafe;

    /* Shadows */
    --shadow-xs:    0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-sm:    0 4px 8px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md:    0 12px 24px rgba(0, 0, 0, 0.06), 0 4px 8px rgba(0, 0, 0, 0.04);
    --shadow-lg:    0 24px 48px rgba(0, 0, 0, 0.08), 0 8px 16px rgba(0, 0, 0, 0.04);
    --shadow-xl:    0 40px 80px rgba(0, 0, 0, 0.10), 0 16px 32px rgba(0, 0, 0, 0.06);
    --shadow-glow:  0 0 40px rgba(249, 115, 22, 0.15);
    --shadow-accent-glow: 0 0 40px rgba(99, 102, 241, 0.12);

    /* Radius */
    --radius-sm:    8px;
    --radius-md:    12px;
    --radius-lg:    20px;
    --radius-xl:    28px;
    --radius-full:  9999px;

    /* Typography Scale */
    --font-body:    'Plus Jakarta Sans', system-ui, sans-serif;
    --font-display: 'Sora', system-ui, sans-serif;

    --text-xs:      0.75rem;
    --text-sm:      0.875rem;
    --text-base:    1rem;
    --text-lg:      1.125rem;
    --text-xl:      1.25rem;
    --text-2xl:     1.5rem;
    --text-3xl:     1.875rem;
    --text-4xl:     2.25rem;
    --text-5xl:     3rem;
    --text-6xl:     3.75rem;

    /* Spacing */
    --space-1:      0.25rem;
    --space-2:      0.5rem;
    --space-3:      0.75rem;
    --space-4:      1rem;
    --space-5:      1.25rem;
    --space-6:      1.5rem;
    --space-8:      2rem;
    --space-10:     2.5rem;
    --space-12:     3rem;
    --space-16:     4rem;
    --space-20:     5rem;
    --space-24:     6rem;
    --space-32:     8rem;

    /* Transitions */
    --transition-fast:   150ms cubic-bezier(0.16, 1, 0.3, 1);
    --transition-base:   250ms cubic-bezier(0.16, 1, 0.3, 1);
    --transition-slow:   400ms cubic-bezier(0.16, 1, 0.3, 1);

    /* Layout */
    --container-max:    1140px;
    --container-narrow: 820px;
    --container-wide:   1300px;

    /* Z-Index Layers */
    --z-base:       0;
    --z-raised:     10;
    --z-dropdown:   100;
    --z-sticky:     200;
    --z-nav:        1000;
    --z-modal:      2000;
    --z-toast:      3000;
}

/* ==========================================================================
   2. RESET & BASE
   ========================================================================== */

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.75;
    color: var(--text-primary);
    background-color: var(--surface-page);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

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

ul, ol {
    list-style: none;
}

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

/* ==========================================================================
   3. TYPOGRAPHY
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.15;
    letter-spacing: -0.025em;
}

h1 { font-size: clamp(2.5rem, 5vw, 3.75rem); }
h2 { font-size: clamp(1.875rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.375rem, 2.5vw, 1.75rem); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p { margin-bottom: var(--space-4); }
p:last-child { margin-bottom: 0; }

.text-lead {
    font-size: var(--text-xl);
    line-height: 1.65;
    color: var(--text-secondary);
    font-weight: 400;
}

.text-muted { color: var(--text-muted); }
.text-faint  { color: var(--text-faint); }
.text-center { text-align: center; }
.text-right  { text-align: right; }

/* Gradient Text */
.gradient-text-primary {
    background: linear-gradient(135deg, var(--brand-primary) 0%, #fb923c 60%, #fdba74 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gradient-text-dark {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 50%, var(--brand-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gradient-text-accent {
    background: linear-gradient(135deg, var(--brand-accent) 0%, #818cf8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ==========================================================================
   4. LAYOUT UTILITIES
   ========================================================================== */

.container {
    max-width: var(--container-max);
    margin-inline: auto;
    padding-inline: var(--space-6);
}

.container--narrow {
    max-width: var(--container-narrow);
    margin-inline: auto;
    padding-inline: var(--space-6);
}

.container--wide {
    max-width: var(--container-wide);
    margin-inline: auto;
    padding-inline: var(--space-6);
}

.section {
    padding-block: var(--space-24);
}

.section--sm {
    padding-block: var(--space-16);
}

.section--lg {
    padding-block: var(--space-32);
}

.section--dark {
    background: var(--surface-dark);
    color: var(--text-inverse);
}

.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--dark h4 {
    color: var(--text-inverse);
}

.section--dark .text-muted {
    color: rgba(255, 255, 255, 0.6);
}

.section--surface {
    background: var(--surface-card);
}

.section--subtle {
    background: var(--surface-subtle);
}

.section--gradient-warm {
    background: linear-gradient(160deg, #fff7ed 0%, #f8fafc 50%, #eff6ff 100%);
}

/* Grids */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-8);
    align-items: center;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-6);
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-5);
}

.grid-auto {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-6);
}

/* Flex Utilities */
.flex         { display: flex; }
.flex-center  { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-col     { display: flex; flex-direction: column; }
.gap-2        { gap: var(--space-2); }
.gap-3        { gap: var(--space-3); }
.gap-4        { gap: var(--space-4); }
.gap-6        { gap: var(--space-6); }
.gap-8        { gap: var(--space-8); }

/* ==========================================================================
   5. NAVIGATION
   ========================================================================== */

.nav-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-default);
    z-index: var(--z-nav);
    padding-block: var(--space-4);
    transition: box-shadow var(--transition-base);
}

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

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-8);
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-family: var(--font-display);
    font-size: var(--text-2xl);
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -0.04em;
    flex-shrink: 0;
}

.nav-logo-mark {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--brand-primary) 0%, var(--brand-primary-dark) 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--text-lg);
    box-shadow: 0 4px 12px rgba(249, 115, 22, 0.3);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.nav-link {
    color: var(--text-muted);
    font-size: var(--text-sm);
    font-weight: 500;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
    background: var(--surface-subtle);
}

/* Dropdown */
.nav-dropdown {
    position: relative;
}

.nav-dropdown-trigger {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    color: var(--text-muted);
    font-size: var(--text-sm);
    font-weight: 500;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    cursor: pointer;
}

.nav-dropdown-trigger:hover {
    color: var(--text-primary);
    background: var(--surface-subtle);
}

.nav-dropdown-trigger svg {
    width: 14px;
    height: 14px;
    transition: transform var(--transition-fast);
}

.nav-dropdown:hover .nav-dropdown-trigger svg {
    transform: rotate(180deg);
}

.nav-dropdown-menu {
    position: absolute;
    top: calc(100% + var(--space-2));
    left: 0;
    background: var(--surface-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    padding: var(--space-2);
    min-width: 220px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all var(--transition-base);
    z-index: var(--z-dropdown);
}

.nav-dropdown:hover .nav-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.nav-dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.nav-dropdown-item:hover {
    background: var(--surface-subtle);
    color: var(--text-primary);
}

.nav-dropdown-item-icon {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    background: var(--brand-primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--brand-primary);
    font-size: var(--text-sm);
    flex-shrink: 0;
}

.nav-cta {
    background: var(--brand-primary);
    color: white;
    padding: var(--space-2) var(--space-5);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(249, 115, 22, 0.25);
    transition: all var(--transition-base);
    flex-shrink: 0;
}

.nav-cta:hover {
    background: var(--brand-primary-dark);
    box-shadow: 0 6px 18px rgba(249, 115, 22, 0.35);
    transform: translateY(-1px);
    color: white;
}

.nav-lang {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--text-muted);
    font-size: var(--text-sm);
    font-weight: 500;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-default);
    transition: all var(--transition-fast);
}

.nav-lang:hover {
    color: var(--text-primary);
    border-color: var(--border-strong);
}

/* Mobile Nav Toggle */
.nav-toggle {
    display: none;
    padding: var(--space-2);
    color: var(--text-primary);
    font-size: var(--text-2xl);
}

/* ==========================================================================
   6. BUTTONS
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: var(--text-base);
    font-weight: 600;
    line-height: 1;
    text-decoration: none;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn--primary {
    background: var(--brand-primary);
    color: white;
    border-color: var(--brand-primary);
    box-shadow: 0 4px 14px rgba(249, 115, 22, 0.25);
}

.btn--primary:hover {
    background: var(--brand-primary-dark);
    border-color: var(--brand-primary-dark);
    box-shadow: 0 8px 24px rgba(249, 115, 22, 0.35);
    transform: translateY(-2px);
    color: white;
}

.btn--secondary {
    background: var(--surface-card);
    color: var(--text-primary);
    border-color: var(--border-default);
    box-shadow: var(--shadow-xs);
}

.btn--secondary:hover {
    border-color: var(--border-strong);
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
}

.btn--dark {
    background: var(--surface-dark);
    color: white;
    border-color: var(--surface-dark);
}

.btn--dark:hover {
    background: var(--surface-dark-muted);
    transform: translateY(-2px);
    color: white;
}

.btn--accent {
    background: var(--brand-accent);
    color: white;
    border-color: var(--brand-accent);
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.25);
}

.btn--accent:hover {
    background: var(--brand-accent-dark);
    transform: translateY(-2px);
    color: white;
}

.btn--ghost {
    background: transparent;
    color: var(--text-secondary);
    border-color: transparent;
}

.btn--ghost:hover {
    background: var(--surface-subtle);
    color: var(--text-primary);
}

.btn--lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-lg);
    border-radius: var(--radius-lg);
}

.btn--sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
}

.btn--full { width: 100%; }

/* ==========================================================================
   7. BADGE / TAG
   ========================================================================== */

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.badge--primary {
    background: var(--brand-primary-light);
    color: var(--brand-primary-dark);
    border: 1px solid rgba(249, 115, 22, 0.2);
}

.badge--accent {
    background: var(--brand-accent-light);
    color: var(--brand-accent-dark);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

.badge--success {
    background: var(--status-success-bg);
    color: var(--status-success);
    border: 1px solid rgba(22, 163, 74, 0.2);
}

.badge--info {
    background: var(--status-info-bg);
    color: var(--status-info);
    border: 1px solid rgba(37, 99, 235, 0.2);
}

.badge--dark {
    background: rgba(15, 23, 42, 0.08);
    color: var(--text-secondary);
    border: 1px solid var(--border-default);
}

.badge--pulse::before {
    content: '';
    display: inline-block;
    width: 6px;
    height: 6px;
    background: currentColor;
    border-radius: var(--radius-full);
    animation: badge-pulse 2s ease-in-out infinite;
}

@keyframes badge-pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50%       { opacity: 0.5; transform: scale(0.85); }
}

/* ==========================================================================
   8. CARDS
   ========================================================================== */

.card {
    background: var(--surface-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.card:hover {
    border-color: var(--border-strong);
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.card--flat {
    box-shadow: none;
}

.card--flat:hover {
    transform: none;
    box-shadow: var(--shadow-sm);
}

.card--highlighted {
    border-color: var(--brand-primary);
    border-width: 2px;
    box-shadow: 0 0 0 4px rgba(249, 115, 22, 0.08), var(--shadow-md);
}

.card--dark {
    background: var(--surface-dark-muted);
    border-color: rgba(255, 255, 255, 0.08);
    color: var(--text-inverse);
}

.card--glass {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-color: rgba(255, 255, 255, 0.5);
}

.card-icon {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: var(--space-5);
    flex-shrink: 0;
}

.card-icon--primary {
    background: var(--brand-primary-light);
    color: var(--brand-primary);
}

.card-icon--accent {
    background: var(--brand-accent-light);
    color: var(--brand-accent);
}

.card-icon--dark {
    background: rgba(15, 23, 42, 0.08);
    color: var(--text-secondary);
}

/* ==========================================================================
   9. STAT / METRIC COMPONENTS
   ========================================================================== */

.stat-card {
    background: var(--surface-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-xl);
    padding: var(--space-6) var(--space-5);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.stat-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.stat-value {
    display: block;
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 800;
    color: var(--brand-primary);
    line-height: 1;
    margin-bottom: var(--space-2);
    letter-spacing: -0.03em;
}

.stat-label {
    color: var(--text-muted);
    font-size: var(--text-sm);
    font-weight: 500;
    line-height: 1.4;
}

/* Metric Row - for VC metrics */
.metric-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) 0;
    border-bottom: 1px solid var(--border-subtle);
}

.metric-row:last-child {
    border-bottom: none;
}

.metric-key {
    font-size: var(--text-sm);
    color: var(--text-muted);
    font-weight: 500;
}

.metric-val {
    font-family: var(--font-display);
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

/* ==========================================================================
   10. HERO SECTION
   ========================================================================== */

.hero {
    padding-block: var(--space-32) var(--space-20);
    text-align: center;
    position: relative;
    overflow: hidden;
    background: var(--surface-page);
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% -20%, rgba(249, 115, 22, 0.08) 0%, transparent 60%),
        radial-gradient(ellipse 60% 40% at 80% 80%, rgba(99, 102, 241, 0.05) 0%, transparent 60%);
    pointer-events: none;
    z-index: 0;
}

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

.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--brand-primary-light);
    color: var(--brand-primary-dark);
    border: 1px solid rgba(249, 115, 22, 0.25);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-6);
}

.hero-headline {
    max-width: 820px;
    margin-inline: auto;
    margin-bottom: var(--space-6);
}

.hero-subline {
    max-width: 640px;
    margin-inline: auto;
    margin-bottom: var(--space-8);
    font-size: var(--text-xl);
    line-height: 1.65;
    color: var(--text-secondary);
}

.hero-actions {
    display: flex;
    gap: var(--space-4);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--space-16);
}

/* ==========================================================================
   11. SECTION HEADERS
   ========================================================================== */

.section-header {
    text-align: center;
    max-width: 680px;
    margin-inline: auto;
    margin-bottom: var(--space-12);
}

.section-eyebrow {
    display: inline-block;
    font-size: var(--text-sm);
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--brand-primary);
    margin-bottom: var(--space-3);
}

.section-title {
    margin-bottom: var(--space-4);
}

.section-subtitle {
    font-size: var(--text-lg);
    color: var(--text-muted);
    line-height: 1.65;
}

/* ==========================================================================
   12. ARCHITECTURE / LAYER DIAGRAM
   ========================================================================== */

.os-layer {
    display: grid;
    grid-template-columns: 160px 1fr auto;
    align-items: center;
    gap: var(--space-6);
    padding: var(--space-5) var(--space-6);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    background: var(--surface-card);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.os-layer::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--layer-color, var(--brand-primary));
}

.os-layer:hover {
    border-color: var(--border-strong);
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.os-layer-number {
    font-family: var(--font-display);
    font-size: var(--text-xs);
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--layer-color, var(--brand-primary));
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.os-layer-title {
    font-family: var(--font-display);
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-1);
    letter-spacing: -0.02em;
}

.os-layer-desc {
    font-size: var(--text-sm);
    color: var(--text-muted);
    margin: 0;
}

.os-layer-badge {
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 600;
    background: rgba(0,0,0,0.04);
    color: var(--text-muted);
    white-space: nowrap;
}

/* ==========================================================================
   13. COMPARISON TABLE
   ========================================================================== */

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.comparison-table th,
.comparison-table td {
    padding: var(--space-4) var(--space-5);
    text-align: left;
    border-bottom: 1px solid var(--border-default);
    font-size: var(--text-sm);
}

.comparison-table th {
    background: var(--surface-subtle);
    font-weight: 700;
    color: var(--text-primary);
    font-family: var(--font-display);
}

.comparison-table th.col-riverova {
    background: var(--brand-primary);
    color: white;
    text-align: center;
}

.comparison-table td.col-riverova {
    background: rgba(249, 115, 22, 0.04);
    text-align: center;
    font-weight: 600;
    color: var(--text-primary);
}

.comparison-table td.col-legacy {
    color: var(--text-muted);
}

.comparison-table tr:last-child td {
    border-bottom: none;
}

.check-yes {
    color: var(--status-success);
    font-size: var(--text-lg);
}

.check-no {
    color: var(--text-faint);
    font-size: var(--text-lg);
}

/* ==========================================================================
   14. TIMELINE / ROADMAP
   ========================================================================== */

.roadmap {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.roadmap-item {
    display: grid;
    grid-template-columns: 80px 1px 1fr;
    gap: 0 var(--space-6);
    padding-bottom: var(--space-8);
}

.roadmap-item:last-child {
    padding-bottom: 0;
}

.roadmap-time {
    text-align: right;
    padding-top: var(--space-1);
}

.roadmap-time-label {
    font-family: var(--font-display);
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--brand-primary);
    white-space: nowrap;
}

.roadmap-line {
    position: relative;
    display: flex;
    justify-content: center;
}

.roadmap-line::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: -var(--space-8);
    width: 1px;
    background: var(--border-default);
}

.roadmap-dot {
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: var(--brand-primary);
    border: 3px solid var(--surface-card);
    box-shadow: 0 0 0 2px var(--brand-primary);
    position: relative;
    z-index: 1;
    margin-top: var(--space-1);
    flex-shrink: 0;
}

.roadmap-content {
    padding-bottom: var(--space-8);
}

.roadmap-content-title {
    font-family: var(--font-display);
    font-size: var(--text-lg);
    font-weight: 700;
    margin-bottom: var(--space-2);
}

/* ==========================================================================
   15. FOOTER
   ========================================================================== */

.footer {
    background: var(--surface-card);
    border-top: 1px solid var(--border-default);
    padding-top: var(--space-20);
    padding-bottom: var(--space-8);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: var(--space-12);
    margin-bottom: var(--space-12);
}

.footer-logo {
    font-family: var(--font-display);
    font-size: var(--text-2xl);
    font-weight: 800;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-4);
    letter-spacing: -0.04em;
}

.footer-tagline {
    color: var(--text-muted);
    font-size: var(--text-sm);
    line-height: 1.7;
    margin-bottom: var(--space-5);
}

.footer-social {
    display: flex;
    gap: var(--space-3);
}

.footer-social-link {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-default);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: var(--text-base);
    transition: all var(--transition-fast);
}

.footer-social-link:hover {
    color: var(--brand-primary);
    border-color: rgba(249, 115, 22, 0.3);
    background: var(--brand-primary-light);
}

.footer-col-title {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-4);
    letter-spacing: 0.02em;
}

.footer-col-links {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer-col-link {
    color: var(--text-muted);
    font-size: var(--text-sm);
    font-weight: 400;
    transition: color var(--transition-fast);
}

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

.footer-legal-box {
    background: var(--surface-subtle);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: var(--space-4);
    font-size: var(--text-xs);
    color: var(--text-muted);
    line-height: 1.7;
}

.footer-legal-box strong {
    display: block;
    color: var(--text-secondary);
    margin-bottom: var(--space-1);
    font-size: var(--text-sm);
}

.footer-bottom {
    border-top: 1px solid var(--border-default);
    padding-top: var(--space-6);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    flex-wrap: wrap;
}

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

.footer-bottom-link {
    font-weight: 600;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

/* ==========================================================================
   16. DECORATIVE ELEMENTS
   ========================================================================== */

.glow-primary {
    position: absolute;
    border-radius: var(--radius-full);
    background: radial-gradient(circle, rgba(249, 115, 22, 0.12) 0%, transparent 70%);
    filter: blur(40px);
    pointer-events: none;
}

.divider {
    height: 1px;
    background: var(--border-default);
    margin-block: var(--space-8);
}

.divider--gradient {
    background: linear-gradient(to right, transparent, var(--border-default), transparent);
}

/* Check List */
.check-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.check-list-item {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
    font-size: var(--text-base);
    color: var(--text-secondary);
}

.check-list-item::before {
    content: '\2713';
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    background: var(--brand-primary-light);
    color: var(--brand-primary);
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 3px;
}

/* Blockquote / Pull Quote */
.pull-quote {
    border-left: 4px solid var(--brand-primary);
    padding-left: var(--space-6);
    padding-block: var(--space-2);
    margin-block: var(--space-8);
}

.pull-quote p {
    font-size: var(--text-xl);
    font-family: var(--font-display);
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.5;
    font-style: italic;
}

/* Page Header (sub-pages) */
.page-header {
    padding-top: calc(var(--space-32) + 70px);
    padding-bottom: var(--space-16);
    text-align: center;
    background: var(--surface-page);
    border-bottom: 1px solid var(--border-default);
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse 80% 80% at 50% -10%, rgba(249, 115, 22, 0.06) 0%, transparent 60%);
    pointer-events: none;
}

.page-header > * { position: relative; z-index: 1; }

/* ==========================================================================
   17. FORM ELEMENTS
   ========================================================================== */

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.form-label {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-secondary);
}

.form-input {
    padding: var(--space-3) var(--space-4);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: var(--text-base);
    color: var(--text-primary);
    background: var(--surface-card);
    transition: all var(--transition-fast);
    outline: none;
}

.form-input:focus {
    border-color: var(--brand-primary);
    box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.12);
}

/* ==========================================================================
   18. ANIMATIONS
   ========================================================================== */

@keyframes fade-in-up {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes fade-in {
    from { opacity: 0; }
    to   { opacity: 1; }
}

@keyframes scale-in {
    from { opacity: 0; transform: scale(0.96); }
    to   { opacity: 1; transform: scale(1); }
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50%       { transform: translateY(-8px); }
}

.animate-fade-in-up {
    animation: fade-in-up 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }
.animate-delay-3 { animation-delay: 0.3s; }
.animate-delay-4 { animation-delay: 0.4s; }

/* Intersection Observer powered animations */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==========================================================================
   19. RESPONSIVE
   ========================================================================== */

@media (max-width: 1100px) {
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .grid-4      { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 960px) {
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .nav-links    { display: none; flex-direction: column; }
    .nav-links.is-open { display: flex; position: absolute; top: 100%; left: 0; width: 100%; background: var(--surface-card); border-bottom: 1px solid var(--border-default); padding: var(--space-4) var(--space-6); gap: var(--space-3); z-index: var(--z-nav); box-shadow: var(--shadow-lg); }
    .nav-toggle   { display: flex; }
    .nav-dropdown-menu { position: static; box-shadow: none; border: none; padding-left: var(--space-4); opacity: 1; visibility: visible; transform: none; }

    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .footer-grid  { grid-template-columns: 1fr; }

    .hero         { padding-block: calc(var(--space-20) + 70px) var(--space-12); }
    .hero-actions { flex-direction: column; align-items: stretch; }
    .hero-actions .btn { justify-content: center; }

    .os-layer { grid-template-columns: 1fr; }
    .os-layer-badge { width: fit-content; }

    .roadmap-item { grid-template-columns: 60px 1px 1fr; }

    .section  { padding-block: var(--space-16); }

    .comparison-table { font-size: var(--text-xs); }
    .comparison-table th,
    .comparison-table td { padding: var(--space-3); }
}

@media (max-width: 480px) {
    h1 { font-size: 2.25rem; }
    h2 { font-size: 1.75rem; }
    .container { padding-inline: var(--space-4); }
}

/* ==========================================================================
   20. GOOGLE ANALYTICS (script handled in HTML) — No CSS needed
   ========================================================================== */