/* ==========================================================================
   AUTOMIVEX TECHNICAL LEARNING PLATFORM — THEME & DESIGN SYSTEM
   Aesthetic Archetype: Neo-Terminal Obsidian & Electric Signal Emerald / Cyan
   Design Standards: High-Density Developer Platform (Linear / Supabase / Warp)
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. DESIGN TOKENS & DUAL-THEME ENGINE
   -------------------------------------------------------------------------- */
:root {
  /* Layout Dimensions */
  --topbar-height: 60px;
  --container-max: 1120px;
  --container-narrow: 820px;

  /* Typography Stacks */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  --font-heading: "Manrope", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;

  /* 8-Point Calibrated Spacing Scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-7: 32px;
  --space-8: 48px;
  --space-9: 64px;

  /* Strict Unified Corner Radii */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;
}

/* ==========================================================================
   DARK THEME: Neo-Terminal Obsidian & Electric Signals (Default)
   ========================================================================== */
:root, [data-theme="dark"] {
  /* Obsidian Canvas & Surface Ladder */
  --bg-canvas: #090d16;
  --bg-canvas-deep: #060910;
  --bg-surface: #0f1523;
  --bg-surface-elevated: #151d30;
  --bg-surface-hover: #1b263e;
  --bg-surface-active: #22304d;
  --bg-input: #0b101b;

  /* Precision Hairline Borders */
  --border-hairline: rgba(255, 255, 255, 0.07);
  --border-default: rgba(255, 255, 255, 0.12);
  --border-hover: rgba(255, 255, 255, 0.24);
  --border-focus: #38bdf8;

  /* Typography & Ink Scale (WCAG AAA Compliant) */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #8493a7;
  --text-subtle: #718096;
  --text-inverse: #090d16;

  /* Chromatic Signals */
  --cyan: #38bdf8;
  --cyan-hover: #0ea5e9;
  --cyan-active: #0284c7;
  --cyan-soft: rgba(56, 189, 248, 0.10);
  --cyan-border: rgba(56, 189, 248, 0.28);

  --emerald: #10b981;
  --emerald-hover: #059669;
  --emerald-soft: rgba(16, 185, 129, 0.10);
  --emerald-border: rgba(16, 185, 129, 0.28);

  --violet: #818cf8;
  --violet-soft: rgba(129, 140, 248, 0.10);
  --violet-border: rgba(129, 140, 248, 0.28);

  --amber: #f59e0b;
  --amber-soft: rgba(245, 158, 11, 0.10);
  --amber-border: rgba(245, 158, 11, 0.28);

  --rose: #f43f5e;
  --rose-soft: rgba(244, 63, 94, 0.10);
  --rose-border: rgba(244, 63, 94, 0.28);

  /* Materials & Components */
  --dot-grid: rgba(255, 255, 255, 0.04);
  --track-bg: rgba(255, 255, 255, 0.08);
  --code-window-bg: #070a12;
  --code-bar-bg: #0c101c;
  --code-text: #e2e8f0;

  --cert-sheet-bg: #0b1120;
  --cert-inner-bg: #080d19;
  --cert-name-color: #fbbf24;
  --cert-border-gold: rgba(245, 158, 11, 0.40);

  --scrollbar-thumb: #151d30;
  --scrollbar-track: #090d16;
  --selection-bg: rgba(56, 189, 248, 0.28);
  --selection-color: #ffffff;

  /* Semantic Aliases */
  --bg-elevated: var(--bg-surface-elevated);
  --danger: var(--rose);
  --danger-hover: var(--rose-soft);

  /* Tactile Machined Surface Elevation */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.5), inset 0 1px 0 0 rgba(255, 255, 255, 0.06);
  --shadow-lg: 0 12px 28px -4px rgba(0, 0, 0, 0.6), inset 0 1px 0 0 rgba(255, 255, 255, 0.08);
}

/* ==========================================================================
   LIGHT THEME: Precision Architectural Slate (High-Contrast Developer Mode)
   ========================================================================== */
[data-theme="light"] {
  /* Slate Canvas & Surface Ladder */
  --bg-canvas: #f8fafc;
  --bg-canvas-deep: #f1f5f9;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f1f5f9;
  --bg-surface-hover: #e2e8f0;
  --bg-surface-active: #cbd5e1;
  --bg-input: #ffffff;

  /* Precision Hairline Borders */
  --border-hairline: rgba(15, 23, 42, 0.07);
  --border-default: rgba(15, 23, 42, 0.13);
  --border-hover: rgba(15, 23, 42, 0.24);
  --border-focus: #0284c7;

  /* Typography & Ink Scale (WCAG AAA Compliant) */
  --text-primary: #090d16;
  --text-secondary: #475569;
  --text-muted: #586779;
  --text-subtle: #586779;
  --text-inverse: #ffffff;

  /* Chromatic Signals (Calibrated for light surfaces) */
  --cyan: #0369a1;
  --cyan-hover: #075985;
  --cyan-active: #0c4a6e;
  --cyan-soft: rgba(2, 132, 199, 0.08);
  --cyan-border: rgba(2, 132, 199, 0.24);

  --emerald: #047857;
  --emerald-hover: #065f46;
  --emerald-soft: rgba(5, 150, 105, 0.08);
  --emerald-border: rgba(5, 150, 105, 0.24);

  --violet: #4f46e5;
  --violet-soft: rgba(99, 102, 241, 0.08);
  --violet-border: rgba(99, 102, 241, 0.24);

  --amber: #92400e;
  --amber-soft: rgba(146, 64, 14, 0.08);
  --amber-border: rgba(146, 64, 14, 0.24);

  --rose: #be123c;
  --rose-soft: rgba(225, 29, 72, 0.08);
  --rose-border: rgba(225, 29, 72, 0.24);

  /* Materials & Components */
  --dot-grid: rgba(15, 23, 42, 0.05);
  --track-bg: rgba(15, 23, 42, 0.08);
  --code-window-bg: #0f172a;
  --code-bar-bg: #090d16;
  --code-text: #f1f5f9;

  --cert-sheet-bg: #ffffff;
  --cert-inner-bg: #fcfbf9;
  --cert-name-color: #b45309;
  --cert-border-gold: rgba(217, 119, 6, 0.45);

  --scrollbar-thumb: #cbd5e1;
  --scrollbar-track: #f8fafc;
  --selection-bg: rgba(2, 132, 199, 0.20);
  --selection-color: #090d16;

  /* Semantic Aliases */
  --bg-elevated: var(--bg-surface-elevated);
  --danger: var(--rose);
  --danger-hover: var(--rose-soft);

  /* Tactile Machined Surface Elevation */
  --shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.08), inset 0 1px 0 0 rgba(255, 255, 255, 0.8);
  --shadow-lg: 0 12px 28px -4px rgba(15, 23, 42, 0.12), inset 0 1px 0 0 rgba(255, 255, 255, 0.9);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg-canvas: #f8fafc;
    --bg-canvas-deep: #f1f5f9;
    --bg-surface: #ffffff;
    --bg-surface-elevated: #f1f5f9;
    --bg-surface-hover: #e2e8f0;
    --bg-surface-active: #cbd5e1;
    --bg-input: #ffffff;

    --border-hairline: rgba(15, 23, 42, 0.07);
    --border-default: rgba(15, 23, 42, 0.13);
    --border-hover: rgba(15, 23, 42, 0.24);
    --border-focus: #0284c7;

    --text-primary: #090d16;
    --text-secondary: #475569;
    --text-muted: #586779;
    --text-subtle: #586779;
    --text-inverse: #ffffff;

    --cyan: #0369a1;
    --cyan-hover: #075985;
    --cyan-active: #0c4a6e;
    --cyan-soft: rgba(2, 132, 199, 0.08);
    --cyan-border: rgba(2, 132, 199, 0.24);

    --emerald: #047857;
    --emerald-hover: #065f46;
    --emerald-soft: rgba(5, 150, 105, 0.08);
    --emerald-border: rgba(5, 150, 105, 0.24);

    --violet: #4f46e5;
    --violet-soft: rgba(99, 102, 241, 0.08);
    --violet-border: rgba(99, 102, 241, 0.24);

    --amber: #92400e;
    --amber-soft: rgba(146, 64, 14, 0.08);
    --amber-border: rgba(146, 64, 14, 0.24);

    --rose: #be123c;
    --rose-soft: rgba(190, 18, 60, 0.08);
    --rose-border: rgba(190, 18, 60, 0.24);

    --dot-grid: rgba(15, 23, 42, 0.05);
    --track-bg: rgba(15, 23, 42, 0.08);
    --code-window-bg: #0f172a;
    --code-bar-bg: #090d16;
    --code-text: #f1f5f9;

    --cert-sheet-bg: #ffffff;
    --cert-inner-bg: #fcfbf9;
    --cert-name-color: #b45309;
    --cert-border-gold: rgba(217, 119, 6, 0.45);

    --scrollbar-thumb: #cbd5e1;
    --scrollbar-track: #f8fafc;
    --selection-bg: rgba(2, 132, 199, 0.20);
    --selection-color: #090d16;

    --bg-elevated: var(--bg-surface-elevated);
    --danger: var(--rose);
    --danger-hover: var(--rose-soft);

    --shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, 0.05);
    --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.08), inset 0 1px 0 0 rgba(255, 255, 255, 0.8);
    --shadow-lg: 0 12px 28px -4px rgba(15, 23, 42, 0.12), inset 0 1px 0 0 rgba(255, 255, 255, 0.9);
  }
}

/* --------------------------------------------------------------------------
   2. GLOBAL BASE & RESET
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
}

/* Precision Selection */
::selection {
  background: var(--selection-bg);
  color: var(--selection-color);
}

/* Custom Tactical Scrollbars */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--border-default) var(--scrollbar-track);
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border: 2px solid var(--scrollbar-track);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-subtle);
}

html {
  scroll-behavior: smooth;
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.55;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 200ms ease, color 200ms ease;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  background-image: radial-gradient(var(--dot-grid) 1px, transparent 1px);
  background-size: 28px 28px;
  overflow-x: hidden;
  transition: background-color 200ms ease, color 200ms ease;
}

#app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  width: 100%;
}

a {
  color: var(--cyan);
  text-decoration: none;
  transition: color 150ms ease;
}

a:hover {
  color: var(--cyan-hover);
  text-decoration: none;
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 2px;
}

h1, h2, h3, h4, h5, p {
  margin-top: 0;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: var(--text-primary);
  font-weight: 700;
  text-wrap: balance;
  letter-spacing: -0.025em;
}

/* --------------------------------------------------------------------------
   3. STRUCTURAL CONTAINERS
   -------------------------------------------------------------------------- */
.container {
  width: min(var(--container-max), calc(100% - 32px));
  margin-inline: auto;
}

.container.narrow {
  width: min(var(--container-narrow), calc(100% - 32px));
  margin-inline: auto;
}

.boot {
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  color: var(--text-secondary);
  font-size: 13px;
  text-align: center;
  padding: var(--space-4);
}

.boot-logo {
  display: block;
  width: min(220px, 72vw);
  height: auto;
}

.boot-logo-dark {
  display: none;
}

:root:not([data-theme="light"]) .boot-logo-light,
[data-theme="dark"] .boot-logo-light,
:root:not([data-theme="light"]) .boot-logo-dark,
[data-theme="dark"] .boot-logo-dark {
  display: none;
}

:root:not([data-theme="light"]) .boot-logo-dark,
[data-theme="dark"] .boot-logo-dark {
  display: block;
}

.boot-indicator {
  width: 112px;
  height: 3px;
  overflow: hidden;
  border-radius: var(--radius-full);
  background: var(--track-bg);
}

.boot-indicator span {
  display: block;
  width: 42%;
  height: 100%;
  border-radius: inherit;
  background: var(--cyan);
  animation: boot-progress 1.35s ease-in-out infinite;
}

.boot p {
  margin: 0;
  font-size: 12px;
}

@keyframes boot-progress {
  from { transform: translateX(-110%); }
  to { transform: translateX(250%); }
}

@media (prefers-reduced-motion: reduce) {
  .boot-indicator span {
    width: 100%;
    animation: none;
  }
}

/* --------------------------------------------------------------------------
   4. NAVIGATION & TOPBAR
   -------------------------------------------------------------------------- */
.topbar {
  min-height: var(--topbar-height);
  border-bottom: 1px solid var(--border-hairline);
  background-color: color-mix(in srgb, var(--bg-canvas) 94%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  position: sticky;
  top: 0;
  z-index: 40;
  box-shadow: 0 1px 0 color-mix(in srgb, var(--border-hairline) 75%, transparent);
}

.nav {
  min-height: var(--topbar-height);
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: var(--space-6);
}

.brand {
  display: inline-flex;
  align-items: center;
  width: 184px;
  color: var(--text-primary);
  font-family: var(--font-heading);
  text-decoration: none;
  flex-shrink: 0;
}

.brand-logo {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: contain;
}

.brand-logo-dark {
  display: none;
}

:root:not([data-theme="light"]) .brand .brand-logo-light,
[data-theme="dark"] .brand .brand-logo-light {
  display: none;
}

:root:not([data-theme="light"]) .brand .brand-logo-dark,
[data-theme="dark"] .brand .brand-logo-dark {
  display: block;
}

.nav-links {
  display: flex;
  flex: 1;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-width: 0;
  margin: 0;
  padding: 0;
}

.nav-links a {
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 150ms ease, background-color 150ms ease;
}

.nav-links a:hover {
  color: var(--text-primary);
  background-color: var(--bg-surface-elevated);
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 0 0 auto;
  margin-left: 0;
}

/* --------------------------------------------------------------------------
   THEME TOGGLE CONTROLS
   -------------------------------------------------------------------------- */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  cursor: pointer;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease, transform 150ms ease;
  flex-shrink: 0;
  padding: 0;
}

.theme-toggle:hover {
  background-color: var(--bg-surface-hover);
  border-color: var(--border-hover);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.theme-toggle:active {
  transform: scale(0.96);
}

.theme-toggle svg {
  width: 15px;
  height: 15px;
}

/* Default / Dark Mode: Show Sun icon to switch to light */
:root:not([data-theme="light"]) .sun-icon,
[data-theme="dark"] .sun-icon {
  display: block;
}
:root:not([data-theme="light"]) .moon-icon,
[data-theme="dark"] .moon-icon {
  display: none;
}

/* Light Mode: Show Moon icon to switch to dark */
[data-theme="light"] .sun-icon {
  display: none;
}
[data-theme="light"] .moon-icon {
  display: block;
}

.mobile-nav-group {
  display: none;
  align-items: center;
  gap: var(--space-2);
}

.legal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-6);
}

.legal-header .brand {
  margin-bottom: 0;
}

.nav-user {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0 var(--space-2);
  max-width: 140px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.mobile-menu {
  display: none;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  background-color: var(--bg-surface);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  min-width: 40px;
  min-height: 40px;
}

.mobile-links {
  display: none;
}

.mobile-links.open {
  display: flex;
  flex-direction: column;
  padding: var(--space-3) max(16px, calc((100% - var(--container-max)) / 2));
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-hairline);
  box-shadow: var(--shadow-md);
  gap: var(--space-1);
}

.mobile-links a {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  padding: 11px 12px;
  border-radius: var(--radius-sm);
}

.mobile-links a:hover {
  background-color: var(--bg-surface-elevated);
}

.mobile-cta {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-top: var(--space-3);
  border-top: 1px solid var(--border-hairline);
  margin-top: var(--space-2);
}

/* --------------------------------------------------------------------------
   5. BUTTONS & INTERACTIVE CONTROLS
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: 38px;
  padding: 0 var(--space-4);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease, box-shadow 150ms ease;
  user-select: none;
  text-align: center;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

.btn.is-loading {
  opacity: 0.82;
  cursor: progress;
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
  white-space: nowrap;
}

.btn-loading-label {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.btn-spinner {
  width: 14px;
  height: 14px;
  flex: 0 0 14px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: button-spin 700ms linear infinite;
}

@keyframes button-spin {
  to { transform: rotate(360deg); }
}

.btn.primary {
  background-color: var(--cyan);
  color: var(--text-inverse);
  font-weight: 700;
  box-shadow: var(--shadow-sm);
}

.btn.primary:hover {
  background-color: var(--cyan-hover);
  box-shadow: 0 0 16px var(--cyan-soft);
}

.btn.primary:active {
  background-color: var(--cyan-active);
}

.btn.soft {
  background-color: var(--cyan-soft);
  color: var(--cyan);
  border-color: var(--cyan-border);
}

.btn.soft:hover {
  background-color: var(--cyan-border);
  border-color: var(--cyan);
}

.btn.outline {
  background-color: var(--bg-surface);
  color: var(--text-primary);
  border-color: var(--border-default);
  box-shadow: var(--shadow-sm);
}

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

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

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

.btn.light-btn {
  background-color: var(--text-primary);
  color: var(--text-inverse);
  font-weight: 700;
}

.btn.light-btn:hover {
  opacity: 0.92;
  transform: translateY(-1px);
}

.btn.small {
  height: 32px;
  padding: 0 var(--space-3);
  font-size: 12px;
}

.btn.tiny {
  height: 26px;
  padding: 0 var(--space-2);
  font-size: 11px;
}

.btn.large {
  height: 44px;
  padding: 0 var(--space-6);
  font-size: 14px;
}

.btn.full {
  width: 100%;
}

.btn.text-btn {
  height: auto;
  padding: 0;
  background: transparent;
  color: var(--cyan);
  font-weight: 600;
}

.btn.text-btn:hover {
  color: var(--cyan-hover);
  text-decoration: underline;
}

/* --------------------------------------------------------------------------
   6. TYPOGRAPHY & MICRO-ELEMENTS
   -------------------------------------------------------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--emerald);
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}

.eyebrow.light {
  color: var(--cyan);
}

.eyebrow-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background-color: var(--emerald);
  box-shadow: 0 0 8px var(--emerald);
  margin-right: var(--space-2);
  flex-shrink: 0;
}

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

.small {
  font-size: 12px;
}

.lead {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
}

.section {
  padding: var(--space-9) 0;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: var(--space-7);
  margin-bottom: var(--space-7);
}

.section-heading h2 {
  font-size: clamp(26px, 3.2vw, 36px);
  line-height: 1.15;
  margin: var(--space-2) 0 0;
}

.section-heading h2 span, .hero h1 span, .capstone-grid h2 span {
  color: var(--cyan);
}

.section-heading > p {
  max-width: 440px;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
  margin: 0;
}

/* --------------------------------------------------------------------------
   7. HERO SECTION (HIGH-DENSITY & ARCHITECTURAL)
   -------------------------------------------------------------------------- */
.hero {
  background-color: var(--bg-canvas);
  border-bottom: 1px solid var(--border-hairline);
  padding: var(--space-9) 0;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  align-items: center;
  gap: var(--space-8);
}

.hero h1 {
  font-size: clamp(34px, 4.4vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.035em;
  margin: var(--space-3) 0 var(--space-4);
  color: var(--text-primary);
}

.hero-lead {
  font-size: 16px;
  line-height: 1.65;
  color: var(--text-secondary);
  max-width: 540px;
  margin-bottom: var(--space-6);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
}

.hero-proof {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-top: var(--space-7);
  padding-top: var(--space-5);
  border-top: 1px solid var(--border-hairline);
}

.proof-avatars {
  display: flex;
  flex-shrink: 0;
}

.proof-avatars span {
  margin-left: -6px;
  width: 28px;
  height: 28px;
  border: 2px solid var(--bg-canvas);
  border-radius: var(--radius-full);
  display: grid;
  place-items: center;
  background-color: var(--bg-surface-elevated);
  color: var(--cyan);
  font-size: 10px;
  font-weight: 800;
  font-family: var(--font-mono);
  box-shadow: var(--shadow-sm);
}

.proof-avatars span:first-child {
  margin-left: 0;
}

.proof-avatars span:nth-child(2) {
  color: var(--emerald);
}

.proof-avatars span:nth-child(3) {
  color: var(--violet);
}

.hero-proof strong {
  display: block;
  font-size: 12px;
  color: var(--text-primary);
}

.hero-proof small {
  display: block;
  font-size: 11px;
  color: var(--text-muted);
}

/* Hero Visual: Flat, Clean Developer Code Mockup */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  width: 100%;
}

.code-window {
  width: 100%;
  max-width: 480px;
  background-color: var(--code-window-bg);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.window-bar {
  height: 38px;
  padding: 0 var(--space-4);
  display: flex;
  align-items: center;
  gap: 6px;
  background-color: var(--code-bar-bg);
  border-bottom: 1px solid var(--border-hairline);
}

.window-bar span {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background-color: #273449;
  flex-shrink: 0;
}

.window-bar b {
  margin-left: var(--space-2);
  color: var(--text-secondary);
  font-size: 11px;
  font-family: var(--font-mono);
  font-weight: 500;
}

.code-window pre {
  margin: 0;
  padding: var(--space-5) var(--space-5);
  overflow-x: auto;
  color: var(--code-text);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.85;
  background-color: var(--code-window-bg);
}

.code-window i {
  color: #818cf8;
  font-style: normal;
}

.code-window em {
  color: #34d399;
  font-style: normal;
}

.code-key {
  color: #f472b6;
}

.code-comment {
  color: #64748b;
}

.code-status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  border-top: 1px solid var(--border-hairline);
  padding: var(--space-2) var(--space-4);
  background-color: var(--code-bar-bg);
  color: var(--text-secondary);
  font-size: 11px;
  font-family: var(--font-mono);
}

.code-status span {
  width: 6px;
  height: 6px;
  background-color: var(--emerald);
  border-radius: var(--radius-full);
  box-shadow: 0 0 6px var(--emerald);
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   8. TRUST STRIP
   -------------------------------------------------------------------------- */
.trust-strip {
  border-bottom: 1px solid var(--border-hairline);
  background-color: var(--bg-surface);
}

.trust-inner {
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.trust-inner span {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.trust-inner strong {
  font-family: var(--font-heading);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--text-primary);
}

.trust-inner i {
  width: 3px;
  height: 3px;
  border-radius: var(--radius-full);
  background-color: var(--text-subtle);
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   9. CURRICULUM & PROGRAMME SECTION
   -------------------------------------------------------------------------- */
.program-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  align-items: start;
}

.course-card {
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--bg-surface);
  box-shadow: var(--shadow-md);
}

.course-cover {
  background-color: var(--bg-canvas-deep);
  border-bottom: 1px solid var(--border-hairline);
  padding: var(--space-6) var(--space-6);
  position: relative;
}

.cover-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  font-family: var(--font-mono);
  padding: var(--space-1) var(--space-2);
  border: 1px solid var(--emerald-border);
  border-radius: var(--radius-xs);
  color: var(--emerald);
  background-color: var(--emerald-soft);
}

.cover-title {
  font-family: var(--font-heading);
  font-size: 26px;
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-top: var(--space-4);
}

.cover-title em {
  font-style: normal;
  color: var(--cyan);
}

.cover-code {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: var(--space-2);
}

.course-card-body {
  padding: var(--space-5) var(--space-6);
}

.course-meta {
  display: flex;
  justify-content: space-between;
  gap: var(--space-2);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-transform: uppercase;
  font-family: var(--font-mono);
}

.course-card h3 {
  font-size: 18px;
  margin: var(--space-2) 0 var(--space-2);
}

.course-card p {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
  margin: 0;
}

.tag-row, .capstone-tags, .stack-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tag-row {
  margin-top: var(--space-4);
}

.tag-row span, .capstone-tags span, .stack-grid span {
  font-size: 11px;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-xs);
  padding: 3px 8px;
}

.course-card-foot {
  border-top: 1px solid var(--border-hairline);
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.free-label {
  display: inline-flex;
  align-items: center;
  color: var(--emerald);
  font-size: 11px;
  font-weight: 700;
  font-family: var(--font-mono);
}

.free-label i {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background-color: var(--emerald);
  box-shadow: 0 0 6px var(--emerald);
  margin-right: var(--space-2);
  flex-shrink: 0;
}

.programme-info {
  display: grid;
  gap: var(--space-4);
}

.info-block {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  padding: var(--space-3) 0;
}

.info-number {
  flex: 0 0 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background-color: var(--cyan-soft);
  border: 1px solid var(--cyan-border);
  color: var(--cyan);
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 800;
  font-family: var(--font-mono);
}

.info-block h3 {
  font-size: 15px;
  margin: 0 0 var(--space-1);
}

.info-block p {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.55;
  margin: 0;
}

.programme-info > .btn {
  margin-top: var(--space-2);
}

/* --------------------------------------------------------------------------
   10. CAPSTONE & SYSTEM ARCHITECTURE
   -------------------------------------------------------------------------- */
.dark-section {
  background-color: var(--bg-canvas-deep);
  border-block: 1px solid var(--border-hairline);
  color: var(--text-primary);
}

.capstone-grid {
  display: grid;
  grid-template-columns: 1fr 0.95fr;
  gap: var(--space-8);
  align-items: center;
}

.capstone-grid h2 {
  font-size: clamp(26px, 3.2vw, 36px);
  line-height: 1.15;
  margin: var(--space-2) 0 var(--space-4);
}

.dark-lead {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
  max-width: 540px;
}

.capstone-tags {
  margin: var(--space-5) 0 var(--space-6);
}

.capstone-tags span {
  color: var(--text-secondary);
  border-color: var(--border-default);
  background-color: var(--bg-surface);
}

.architecture-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: grid;
  gap: var(--space-2);
  box-shadow: var(--shadow-md);
}

.arch-label {
  font-size: 10px;
  letter-spacing: 0.1em;
  font-family: var(--font-mono);
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.arch-node {
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-canvas);
  padding: var(--space-3) var(--space-4);
  text-align: center;
  flex: 1;
}

.arch-node b, .arch-node small {
  display: block;
}

.arch-node b {
  font-size: 12px;
  color: var(--text-primary);
}

.arch-node small {
  font-size: 10px;
  color: var(--text-muted);
  margin-top: 2px;
  font-family: var(--font-mono);
}

.main-node {
  border-color: var(--cyan-border);
  background-color: var(--cyan-soft);
}

.api-node {
  border-color: var(--emerald-border);
  background-color: var(--emerald-soft);
}

.db-node {
  border-color: var(--violet-border);
  background-color: var(--violet-soft);
}

.arch-connector {
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1;
}

.arch-row {
  display: flex;
  gap: var(--space-2);
}

.arch-foot {
  border-top: 1px solid var(--border-hairline);
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  display: flex;
  justify-content: space-around;
  color: var(--emerald);
  font-size: 11px;
  font-weight: 600;
  font-family: var(--font-mono);
}

/* --------------------------------------------------------------------------
   11. STEPS & FAQ
   -------------------------------------------------------------------------- */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-3);
}

.step-card {
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  background-color: var(--bg-surface);
  box-shadow: var(--shadow-sm);
  transition: border-color 150ms ease;
  display: flex;
  flex-direction: column;
}

.step-card:hover {
  border-color: var(--border-hover);
}

.step-card > span {
  display: inline-block;
  color: var(--cyan);
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 12px;
  margin-bottom: var(--space-3);
}

.step-card h3 {
  font-size: 14px;
  margin-bottom: var(--space-2);
}

.step-card p {
  color: var(--text-secondary);
  font-size: 12px;
  line-height: 1.55;
  margin: 0;
}

.faq-section {
  background-color: var(--bg-canvas-deep);
  border-top: 1px solid var(--border-hairline);
}

.faq-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: var(--space-8);
}

.faq-grid > div > p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-top: var(--space-3);
}

.faq-list details {
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--border-hairline);
}

.faq-list details:first-child {
  border-top: 1px solid var(--border-hairline);
}

.faq-list summary {
  cursor: pointer;
  list-style: none;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  color: var(--cyan);
  font-size: 18px;
  font-weight: 400;
  line-height: 1;
  flex-shrink: 0;
  min-width: 16px;
  text-align: center;
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-list details p {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.65;
  margin: var(--space-3) 0 0;
}

/* --------------------------------------------------------------------------
   12. CTA & FOOTER
   -------------------------------------------------------------------------- */
.cta-section {
  background-color: var(--bg-surface);
  border-block: 1px solid var(--border-hairline);
  padding: var(--space-8) 0;
  color: var(--text-primary);
}

.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

.cta-inner h2 {
  font-size: 28px;
  line-height: 1.2;
  margin: var(--space-2) 0;
}

.cta-inner p {
  color: var(--text-secondary);
  font-size: 13px;
  margin: 0;
}

.cta-actions {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  align-items: center;
}

.footer {
  background-color: var(--bg-canvas-deep);
  color: var(--text-secondary);
  padding: var(--space-8) 0 var(--space-4);
  border-top: 1px solid var(--border-hairline);
  margin-top: auto;
}

.footer-inner {
  display: block;
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(240px, 1.7fr) repeat(3, minmax(120px, 1fr));
  gap: var(--space-7);
  padding-bottom: var(--space-7);
}

.footer-brand p {
  max-width: 280px;
  font-size: 12px;
  line-height: 1.6;
  margin: var(--space-3) 0 0;
  color: var(--text-muted);
}

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

.footer-brand .brand {
  width: 196px;
}

.footer-link-group {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-2);
}

.footer-link-group b {
  margin-bottom: var(--space-1);
  color: var(--text-primary);
  font-size: 12px;
  font-weight: 700;
}

.footer-link-group a {
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 500;
  text-decoration: none;
  transition: color 150ms ease;
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
  border-top: 1px solid var(--border-hairline);
  padding-top: var(--space-4);
}

.footer-bottom small {
  color: var(--text-muted);
  font-size: 11px;
}

/* --------------------------------------------------------------------------
   13. AUTHENTICATION VIEW & FORMS
   -------------------------------------------------------------------------- */
.auth-wrap {
  background-color: var(--bg-canvas);
  min-height: calc(100vh - var(--topbar-height));
  padding: var(--space-8) var(--space-4);
  display: flex;
  align-items: center;
  justify-content: center;
}

.auth-card {
  width: min(880px, 100%);
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.auth-side {
  background-color: var(--bg-surface-elevated);
  border-right: 1px solid var(--border-hairline);
  padding: var(--space-7) var(--space-6);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.auth-side h2 {
  font-size: 26px;
  line-height: 1.2;
  margin: var(--space-3) 0 var(--space-2);
}

.auth-side p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0;
}

.auth-side-note {
  margin-top: var(--space-6);
  border-top: 1px solid var(--border-hairline);
  padding-top: var(--space-4);
  font-size: 11px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.auth-form-side {
  padding: var(--space-7) var(--space-7);
}

.auth-form-side h1 {
  font-size: 24px;
  margin: var(--space-2) 0 var(--space-1);
}

.auth-mode-toggle {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px;
  margin-top: var(--space-5);
  padding: 4px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
}

.auth-mode-toggle button {
  min-height: 42px;
  border: 0;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-secondary);
  font: inherit;
  font-size: 13px;
  font-weight: 650;
  cursor: pointer;
  transition: background-color 150ms ease, color 150ms ease, box-shadow 150ms ease;
}

.auth-mode-toggle button[aria-pressed="true"] {
  background: var(--bg-surface);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

.auth-mode-toggle button:focus-visible,
.auth-switch-link:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 2px;
}

.auth-mode-copy {
  margin-top: var(--space-3);
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

.auth-code-intro {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-top: var(--space-4);
  padding: var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
}

.auth-code-intro p {
  margin: 0;
  line-height: 1.6;
  overflow-wrap: anywhere;
}

.auth-code-intro b {
  color: var(--text-primary);
}

.auth-code-icon {
  display: grid;
  width: 36px;
  height: 36px;
  flex: 0 0 36px;
  place-items: center;
  border-radius: 50%;
  background: var(--cyan-soft);
  color: var(--cyan);
}

#verify-form input[name="code"] {
  height: 54px;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.3em;
  text-align: center;
}

.auth-switch-link {
  justify-self: center;
  border: 0;
  background: transparent;
  color: var(--cyan);
  font: inherit;
  font-size: 12px;
  font-weight: 650;
  cursor: pointer;
}

.profile-settings-card {
  max-width: 720px;
}

.profile-field-help {
  display: block;
  margin-top: -12px;
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.55;
}

.profile-field-help a,
.profile-certificate-lock a {
  color: var(--cyan);
  font-weight: 650;
}

.profile-settings-card input[readonly],
.profile-settings-card input:disabled {
  opacity: 0.78;
  cursor: not-allowed;
}

.profile-certificate-preview {
  display: grid;
  gap: var(--space-2);
  padding: var(--space-4);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
}

.profile-certificate-preview small {
  color: var(--text-muted);
  font: 700 10px var(--font-mono);
  letter-spacing: 0.08em;
}

.profile-certificate-preview b {
  color: var(--text-primary);
  font-size: 20px;
  overflow-wrap: anywhere;
}

.profile-certificate-preview span {
  color: var(--text-secondary);
  font-size: 12px;
}

.profile-certificate-lock {
  margin: 0;
}

.form {
  display: grid;
  gap: var(--space-4);
  margin-top: var(--space-5);
}

.form label {
  display: grid;
  gap: var(--space-1);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.form input, .form select, .form textarea {
  width: 100%;
  height: 40px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  padding: 0 var(--space-3);
  background-color: var(--bg-input);
  color: var(--text-primary);
  font-size: 13px;
  transition: border-color 150ms ease, box-shadow 150ms ease;
}

.form textarea {
  height: auto;
  min-height: 80px;
  padding: var(--space-2) var(--space-3);
}

.form input:focus, .form textarea:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px var(--cyan-soft);
}

.check-label {
  display: flex !important;
  align-items: flex-start;
  gap: var(--space-2) !important;
  font-weight: 500 !important;
  color: var(--text-secondary) !important;
  line-height: 1.45;
  font-size: 12px !important;
}

.check-label input {
  width: 15px;
  height: 15px;
  margin-top: 3px;
  flex-shrink: 0;
  accent-color: var(--cyan);
}

.auth-foot {
  border-top: 1px solid var(--border-hairline);
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  color: var(--text-muted);
  font-size: 11px;
  line-height: 1.5;
}

.back-link {
  display: inline-flex;
  align-items: center;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
  margin-bottom: var(--space-3);
  transition: color 150ms ease;
}

.back-link:hover {
  color: var(--cyan);
}

.dev-code {
  padding: var(--space-3);
  background-color: var(--amber-soft);
  border: 1px solid var(--amber-border);
  border-radius: var(--radius-sm);
  color: var(--amber);
  font-size: 12px;
  font-family: var(--font-mono);
}

/* --------------------------------------------------------------------------
   14. LESSON CHAPTER VIDEO & PLAYER CONTROLS
   -------------------------------------------------------------------------- */
.lesson-row {
  display: block !important;
}

.lesson-heading {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  width: 100%;
}

.dash-account {
  position: relative;
}

.dash-account-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  z-index: 20;
  width: 220px;
  display: none;
  padding: var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
  box-shadow: var(--shadow-lg);
}

.dash-account-menu.open {
  display: grid;
  gap: 6px;
}

.dash-account-menu b,
.dash-account-menu span {
  overflow-wrap: anywhere;
}

.dash-account-menu span {
  margin-bottom: 6px;
  color: var(--text-muted);
  font-size: 12px;
}

.dash-account-menu button {
  min-height: 38px;
  border: 0;
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--text-primary);
  cursor: pointer;
  text-align: left;
  padding: 8px 10px;
  transition: background-color 150ms ease;
}

.dash-account-menu button:hover {
  background: var(--bg-surface-hover);
}

.dash-account-menu button.danger {
  color: var(--danger);
}

.lesson-check {
  display: grid;
  gap: var(--space-3);
  width: 100%;
  min-width: 0;
}

.lesson-check .form-field {
  display: grid;
  gap: var(--space-2);
  width: 100%;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.45;
}

.lesson-check textarea {
  display: block;
  width: 100%;
  min-height: 120px;
  box-sizing: border-box;
  resize: vertical;
  padding: 12px 14px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-input);
  color: var(--text-primary);
  font: 14px/1.55 var(--font-sans);
  transition: border-color 150ms ease, box-shadow 150ms ease, background-color 150ms ease;
}

.lesson-check textarea::placeholder {
  color: var(--text-muted);
  opacity: 1;
}

.lesson-check textarea:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px var(--cyan-soft);
}

.lesson-choice-list {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.lesson-choice-list label {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  padding: 10px;
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
}

.lesson-resources {
  display: grid;
  gap: 8px;
  margin-top: var(--space-3);
}

.lesson-study {
  margin: 0;
  border: 0;
  border-bottom: 1px solid var(--border-hairline);
  border-radius: 0;
  background-color: var(--bg-surface);
  overflow: hidden;
}

.lesson-study summary {
  cursor: pointer;
  padding: var(--space-3) var(--space-4);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  background-color: var(--bg-surface-elevated);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  user-select: none;
}

.lesson-study[open] summary {
  border-bottom: 1px solid var(--border-hairline);
}

.lesson-study summary b {
  color: var(--cyan);
  font-size: 13px;
}

.lesson-study summary small {
  color: var(--text-muted);
  font-size: 12px;
}

.lesson-duration {
  font-size: 11px;
  font-family: var(--font-mono);
  color: var(--text-muted);
  background-color: var(--bg-canvas);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-hairline);
  flex-shrink: 0;
}

.lesson-study-body {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: var(--space-4);
  padding: var(--space-4);
  align-items: start;
}

.lesson-video-card {
  width: 100%;
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  background: var(--bg-surface);
  box-shadow: var(--shadow-sm);
}

.lesson-video-card.mobile-fullscreen {
  position: fixed;
  z-index: 10000;
  inset: 0;
  display: flex;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  max-width: none;
  max-height: 100dvh;
  flex-direction: column;
  overflow: hidden;
  border: 0;
  border-radius: 0;
  background: #000;
}

.lesson-video-card.mobile-fullscreen .lesson-video-frame {
  min-height: 0;
  flex: 1 1 auto;
  aspect-ratio: auto;
}

.lesson-video-card.mobile-fullscreen .lesson-video-caption,
.lesson-video-card.mobile-fullscreen .lesson-player-status,
.lesson-video-card.mobile-fullscreen .lesson-player-hint,
.lesson-video-card.mobile-fullscreen .lesson-video-chapters {
  display: none;
}

.lesson-video-card.mobile-fullscreen .lesson-video-controls {
  position: absolute;
  z-index: 20;
  right: 0;
  bottom: 0;
  left: 0;
  border: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.92), transparent);
}

.lesson-video-card.mobile-fullscreen .lesson-clip-play,
.lesson-video-card.mobile-fullscreen .lesson-clip-rewind,
.lesson-video-card.mobile-fullscreen .lesson-clip-forward,
.lesson-video-card.mobile-fullscreen .lesson-clip-fullscreen,
.lesson-video-card.mobile-fullscreen .lesson-clip-time {
  color: #fff;
}

.lesson-video-card:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 3px;
}

.lesson-video-card:fullscreen {
  display: flex;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  max-width: none;
  max-height: 100dvh;
  flex-direction: column;
  overflow: hidden;
  position: relative;
  border: 0;
  border-radius: 0;
  background: #000;
}

.lesson-video-card:fullscreen .lesson-video-frame {
  min-height: 0;
  flex: 1 1 auto;
  aspect-ratio: auto;
}

.lesson-video-card:fullscreen .lesson-video-caption,
.lesson-video-card:fullscreen .lesson-player-status,
.lesson-video-card:fullscreen .lesson-player-hint,
.lesson-video-card:fullscreen .lesson-video-chapters {
  display: none;
}

.lesson-video-card:fullscreen .lesson-player-status,
.lesson-video-card:fullscreen .lesson-player-hint {
  flex: 0 0 auto;
}

.lesson-video-card:fullscreen .lesson-video-controls {
  position: absolute;
  z-index: 20;
  right: 0;
  bottom: 0;
  left: 0;
  grid-template-columns: auto auto auto auto minmax(120px, 1fr) auto auto auto auto;
  min-height: 72px;
  padding: 10px clamp(14px, 2vw, 28px) 14px;
  border: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.92) 0%, rgba(0, 0, 0, 0.72) 55%, transparent 100%);
  opacity: 1;
  transform: translateY(0);
  transition: opacity 180ms ease, transform 180ms ease;
}

.lesson-video-card:fullscreen.ui-hidden .lesson-video-controls {
  opacity: 0;
  transform: translateY(calc(100% - 6px));
  pointer-events: none;
}

.lesson-video-card:fullscreen.ui-hidden {
  cursor: none;
}


.lesson-video-card:fullscreen .lesson-clip-play,
.lesson-video-card:fullscreen .lesson-clip-rewind,
.lesson-video-card:fullscreen .lesson-clip-forward,
.lesson-video-card:fullscreen .lesson-clip-fullscreen {
  border-color: transparent;
  border-radius: 50%;
  background: transparent;
  color: #fff;
}

.lesson-video-card:fullscreen .lesson-clip-play {
  min-width: 44px;
  border-radius: 50%;
  background: transparent;
  color: #fff;
}

.lesson-video-card:fullscreen .lesson-clip-rewind,
.lesson-video-card:fullscreen .lesson-clip-forward,
.lesson-video-card:fullscreen .lesson-clip-fullscreen {
  width: 44px;
}

.lesson-video-card:fullscreen .lesson-clip-play:hover:not(:disabled),
.lesson-video-card:fullscreen .lesson-clip-rewind:hover:not(:disabled),
.lesson-video-card:fullscreen .lesson-clip-forward:hover:not(:disabled),
.lesson-video-card:fullscreen .lesson-clip-fullscreen:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.14);
}

.lesson-video-card:fullscreen .lesson-clip-time {
  color: #fff;
}

.lesson-video-card:fullscreen .lesson-clip-volume {
  color: #fff;
}

.lesson-video-card:fullscreen .lesson-clip-seek {
  height: 28px;
  background: linear-gradient(to right, var(--cyan) 0 var(--played, 0%), rgba(255, 255, 255, 0.38) var(--played, 0%) 100%);
}

.lesson-video-card:fullscreen .lesson-clip-seek::-webkit-slider-thumb {
  width: 16px;
  height: 16px;
  border-width: 0;
  background: var(--cyan);
  box-shadow: none;
}

.lesson-video-card:fullscreen .lesson-clip-seek::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-width: 0;
  background: var(--cyan);
  box-shadow: none;
}

.lesson-video-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  min-height: 200px;
  overflow: hidden;
  background: #000;
}

.lesson-video-frame iframe,
.lesson-youtube-target {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  min-width: 100%;
  min-height: 100%;
  border: 0;
  background: #000;
}

.lesson-video-caption {
  display: none;
}

.lesson-video-caption b {
  color: var(--text-primary);
  font-size: 13px;
}

.lesson-video-caption p {
  margin: 3px 0 0;
  color: var(--text-muted);
  font-size: 11px;
  line-height: 1.4;
}

.lesson-video-chapters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-2);
  padding: var(--space-3);
  background: var(--bg-surface-elevated);
}

.lesson-video-chapter {
  display: grid;
  gap: 5px;
  min-width: 0;
  padding: 10px 12px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--text-secondary);
  font: inherit;
  font-size: 12px;
  text-align: left;
  cursor: pointer;
  transition: border-color 150ms ease, background-color 150ms ease, color 150ms ease;
}

.lesson-video-chapter small {
  color: var(--text-muted);
  font: 10px/1.4 var(--font-mono);
}

.lesson-video-chapter:hover,
.lesson-video-chapter.active {
  border-color: var(--cyan-border);
  background: var(--cyan-soft);
  color: var(--text-primary);
}

.lesson-video-chapter.active span {
  color: var(--cyan);
  font-weight: 700;
}

.lesson-video-chapter:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.lesson-video-controls {
  display: grid;
  grid-template-columns: auto auto auto auto minmax(80px, 1fr) auto auto auto;
  align-items: center;
  gap: 10px;
  padding: 12px;
  touch-action: manipulation;
  border-top: 1px solid var(--border-hairline);
  background: var(--bg-surface-elevated);
}

.lesson-clip-play,
.lesson-clip-rewind,
.lesson-clip-forward,
.lesson-clip-fullscreen {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0 12px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--text-primary);
  font: 700 12px/1 var(--font-sans);
  cursor: pointer;
}

.lesson-clip-rewind,
.lesson-clip-forward {
  width: 44px;
  padding: 0;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--text-primary);
  font: 700 11px/1 var(--font-mono);
}

.lesson-clip-rewind:hover:not(:disabled),
.lesson-clip-forward:hover:not(:disabled) {
  border-color: var(--cyan);
  color: var(--cyan);
}

.lesson-clip-play {
  width: 44px;
  min-width: 44px;
  padding: 0;
  border-radius: 50%;
  border-color: var(--cyan);
  background: var(--cyan);
  color: var(--text-inverse);
  font-size: 16px;
}

.lesson-clip-play:hover:not(:disabled) {
  background: var(--cyan-hover);
}

.lesson-clip-play:disabled,
.lesson-clip-rewind:disabled,
.lesson-clip-forward:disabled,
.lesson-clip-fullscreen:disabled,
.lesson-video-controls input:disabled {
  cursor: wait;
  opacity: 0.55;
}

.lesson-clip-play:focus-visible,
.lesson-clip-fullscreen:focus-visible,
.lesson-video-controls input:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 3px;
}

.lesson-clip-fullscreen {
  width: 44px;
  padding: 0;
  font-size: 16px;
}

.lesson-clip-time {
  color: var(--text-muted);
  font: 11px/1 var(--font-mono);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.lesson-clip-seek,
.lesson-clip-volume input {
  margin: 0;
  accent-color: var(--cyan);
  cursor: pointer;
}

.lesson-clip-seek {
  width: 100%;
  height: 24px;
  padding: 0;
  appearance: none;
  border-radius: var(--radius-full);
  background: linear-gradient(to right, var(--cyan) 0 var(--played, 0%), var(--track-bg) var(--played, 0%) 100%);
}

.lesson-clip-seek::-webkit-slider-thumb {
  width: 18px;
  height: 18px;
  appearance: none;
  border: 2px solid var(--bg-surface);
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 1px var(--cyan);
}

.lesson-clip-seek::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border: 2px solid var(--bg-surface);
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 1px var(--cyan);
}

.lesson-clip-volume {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 10px;
  white-space: nowrap;
}

.lesson-clip-volume input {
  width: 72px;
  min-height: 24px;
}

.lesson-player-hint {
  display: none;
}

.lesson-player-status {
  display: none;
}

.lesson-player-status.has-error {
  display: block;
  min-height: 28px;
  margin: 0;
  padding: 7px 12px;
  color: var(--text-muted);
  background: var(--bg-surface);
  font-size: 10px;
  line-height: 1.4;
}

@media (max-width: 480px) {
  .lesson-video-controls {
    grid-template-columns: auto auto minmax(60px, 1fr) auto;
    gap: 8px;
  }
  .lesson-clip-rewind {
    grid-column: 1;
    grid-row: 1;
  }
  .lesson-clip-play {
    grid-column: 2;
    grid-row: 1;
    min-width: 96px;
    padding: 0 10px;
  }
  .lesson-clip-forward {
    grid-column: 3;
    grid-row: 1;
  }
  .lesson-clip-time[data-player="elapsed"] {
    grid-column: 4;
    grid-row: 1;
  }
  .lesson-clip-seek {
    grid-column: 1 / 4;
    grid-row: 2;
  }
  .lesson-clip-time[data-player="duration"] {
    grid-column: 4;
    grid-row: 2;
  }
  .lesson-clip-volume {
    grid-column: 1 / 4;
    grid-row: 3;
    justify-content: flex-end;
  }
  .lesson-clip-fullscreen {
    grid-column: 4;
    grid-row: 2;
  }
  .lesson-video-card:fullscreen .lesson-video-controls {
    grid-template-columns: auto auto auto auto minmax(60px, 1fr) auto auto auto;
    gap: 6px;
  }
  .lesson-video-card:fullscreen .lesson-clip-rewind,
  .lesson-video-card:fullscreen .lesson-clip-play,
  .lesson-video-card:fullscreen .lesson-clip-forward,
  .lesson-video-card:fullscreen .lesson-clip-time,
  .lesson-video-card:fullscreen .lesson-clip-seek,
  .lesson-video-card:fullscreen .lesson-clip-volume,
  .lesson-video-card:fullscreen .lesson-clip-fullscreen {
    grid-column: auto;
    grid-row: auto;
  }
  .lesson-video-card:fullscreen .lesson-clip-volume {
    display: none;
  }
}

.study-overview {
  border-left: 3px solid var(--emerald);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-left-width: 3px;
  border-left-color: var(--emerald);
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-4);
  margin-bottom: var(--space-3);
}

.study-overview span {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--emerald);
  text-transform: uppercase;
  font-family: var(--font-mono);
}

.study-overview p {
  margin: var(--space-1) 0 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

.study-content h4 {
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin: var(--space-3) 0 var(--space-2);
  color: var(--text-primary);
  font-family: var(--font-mono);
}

.study-content ul {
  margin: 0 0 var(--space-3);
  padding-left: var(--space-4);
  color: var(--text-secondary);
  font-size: 13px;
}

.study-content p {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

.study-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.lesson-check-form {
  width: 100%;
  display: grid;
  gap: var(--space-3);
  padding: var(--space-4);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  background-color: var(--bg-surface-elevated);
}

.lesson-check-form fieldset {
  margin: 0;
  padding: 0;
  border: 0;
}

.lesson-check-form legend {
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
  font-size: 13px;
}

.lesson-check-form label {
  display: grid;
  gap: var(--space-1);
  color: var(--text-secondary);
  font-size: 12px;
}

.lesson-check-form fieldset label {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin: var(--space-2) 0;
  cursor: pointer;
}

.lesson-check-form textarea {
  width: 100%;
  min-height: 72px;
  resize: vertical;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-3);
  color: var(--text-primary);
  background-color: var(--bg-input);
}

/* --------------------------------------------------------------------------
   15. QUIZ & ASSESSMENT VIEW
   -------------------------------------------------------------------------- */
.dashboard-main {
  background-color: var(--bg-canvas);
  min-height: calc(100vh - var(--topbar-height));
  padding: var(--space-7) 0 var(--space-8);
}

.assessment-lockdown {
  position: relative;
}

.assessment-watermark {
  position: fixed;
  z-index: 80;
  right: var(--space-4);
  bottom: var(--space-3);
  pointer-events: none;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: color-mix(in srgb, var(--bg-surface-elevated) 95%, transparent);
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 600;
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  opacity: 0.7;
}

.notice {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  margin-bottom: var(--space-4);
}

.notice b {
  font-size: 12px;
  color: var(--text-primary);
}

.notice p {
  color: var(--text-secondary);
  font-size: 12px;
  line-height: 1.6;
  margin: var(--space-1) 0 0;
}

.quiz-form {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.question {
  border: 0;
  border-bottom: 1px solid var(--border-hairline);
  padding: var(--space-5) var(--space-6);
  margin: 0;
}

.question legend {
  width: 100%;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text-primary);
}

.question legend span {
  display: block;
  color: var(--cyan);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.08em;
  font-family: var(--font-mono);
  margin-bottom: var(--space-1);
}

.choice-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.choice {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-3);
  min-height: 44px;
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  font-size: 13px;
  cursor: pointer;
  background-color: var(--bg-canvas);
  color: var(--text-secondary);
  transition: border-color 150ms ease, background-color 150ms ease;
}

.choice:hover {
  border-color: var(--border-hover);
  background-color: var(--bg-surface-elevated);
  color: var(--text-primary);
}

.choice input {
  accent-color: var(--cyan);
  margin: 0;
  flex-shrink: 0;
}

.choice:has(input:checked) {
  background-color: var(--cyan-soft);
  border-color: var(--cyan);
  color: var(--cyan);
  font-weight: 600;
}

.written-evidence {
  padding: var(--space-6);
  border-bottom: 1px solid var(--border-hairline);
  display: grid;
  gap: var(--space-4);
}

.written-evidence .form-field {
  display: grid;
  gap: var(--space-2);
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 700;
}

.written-evidence textarea {
  width: 100%;
  min-height: 96px;
  resize: vertical;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  padding: var(--space-3);
  color: var(--text-primary);
  background-color: var(--bg-input);
  font: inherit;
}

.written-evidence textarea:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.choice.declaration {
  margin-top: var(--space-2);
  background-color: var(--bg-surface);
  border-color: var(--border-hairline);
}

/* --------------------------------------------------------------------------
   16. ADMIN & METRICS VIEW
   -------------------------------------------------------------------------- */
.admin-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin: var(--space-5) 0;
}

.admin-stats > div {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
}

.admin-stats small {
  display: block;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-family: var(--font-mono);
}

.admin-stats b {
  display: block;
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 800;
  margin-top: var(--space-1);
  color: var(--text-primary);
}

.table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

th, td {
  text-align: left;
  border-bottom: 1px solid var(--border-hairline);
  padding: var(--space-3) var(--space-3);
  white-space: nowrap;
}

th {
  color: var(--text-muted);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  background-color: var(--bg-surface-elevated);
}

td small {
  display: block;
  color: var(--text-muted);
  font-size: 11px;
  margin-top: 2px;
}

.status-pill {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  font-family: var(--font-mono);
  padding: 3px 8px;
  border-radius: var(--radius-full);
  background-color: var(--amber-soft);
  color: var(--amber);
  border: 1px solid var(--amber-border);
}

.status-pill.good {
  background-color: var(--emerald-soft);
  color: var(--emerald);
  border-color: var(--emerald-border);
}

.capstone-submission-review {
  margin: var(--space-5) 0;
  padding: clamp(16px, 3vw, 24px);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  background: var(--bg-surface-elevated);
  scroll-margin-top: var(--space-6);
}

.capstone-submission-review-heading,
.capstone-review-links {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.capstone-submission-review-heading h3 {
  margin: 4px 0;
  font-size: clamp(18px, 3vw, 22px);
}

.capstone-submission-review-heading p,
.capstone-submission-review-detail p,
.capstone-checks-heading p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

.capstone-submission-review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr));
  gap: var(--space-4);
  margin: var(--space-5) 0;
}

.capstone-submission-review-detail {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-2);
  min-width: 0;
  padding: var(--space-4);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface);
}

.capstone-submission-review-detail > small,
.capstone-submission-review .social-attestation-status {
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.capstone-repository-url {
  max-width: 100%;
  color: var(--text-primary);
  font-weight: 650;
  overflow-wrap: anywhere;
}

.capstone-review-links {
  justify-content: flex-start;
  margin-top: var(--space-2);
}

.capstone-review-links .btn {
  min-height: 38px;
}

.capstone-checks-heading {
  margin: var(--space-4) 0 var(--space-2);
}

.capstone-checks-heading h4 {
  margin: 0 0 4px;
  font-size: 14px;
}

.capstone-submission-review .repo-check-list {
  margin-top: var(--space-3);
}

.capstone-submission-review .social-attestation-status {
  display: block;
  margin-top: var(--space-4);
  line-height: 1.6;
}

#project-submission {
  scroll-margin-top: var(--space-6);
}

.review-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  min-width: 150px;
}

.review-note {
  display: block;
  max-width: 220px;
  color: var(--text-secondary);
  line-height: 1.45;
  overflow-wrap: anywhere;
  margin-top: var(--space-2);
}

.admin-certificates .table-wrap {
  margin-top: var(--space-4);
}

.certificate-search {
  display: grid;
  gap: var(--space-2);
  max-width: 640px;
  margin: var(--space-4) 0;
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 650;
}

.certificate-search > div {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.certificate-search input {
  width: min(100%, 420px);
  min-height: 42px;
  padding: 9px 12px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  color: var(--text-primary);
  font: inherit;
  font-weight: 400;
}

.certificate-name-correction {
  display: grid;
  min-width: 240px;
  gap: var(--space-2);
}

.admin-certificate-actions {
  display: grid;
  justify-items: start;
  gap: var(--space-3);
}

.admin-certificate-actions > .btn {
  max-width: 100%;
}

.certificate-name-correction label {
  display: grid;
  gap: 5px;
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 650;
}

.certificate-name-correction input,
.certificate-name-correction textarea {
  width: 100%;
  min-height: 38px;
  padding: 8px 10px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  color: var(--text-primary);
  font: inherit;
  font-size: 12px;
}

.certificate-name-correction textarea {
  min-height: 62px;
  resize: vertical;
}

.certificate-name-correction input:focus,
.certificate-name-correction textarea:focus {
  border-color: var(--border-focus);
  outline: 3px solid var(--cyan-soft);
}

.panel {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.panel h2 {
  font-size: 18px;
  margin-bottom: var(--space-3);
}

.requirement-list {
  padding-left: var(--space-5);
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.8;
  margin: 0;
}

.certificate-feature-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.certificate-feature-actions .btn {
  min-height: 40px;
}

.certificate-linkedin-guide {
  max-width: 680px;
}

.certificate-steps {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  align-items: stretch;
  gap: var(--space-3);
}

.certificate-steps > div {
  display: flex;
  min-width: 0;
  min-height: 190px;
  flex-direction: column;
  align-items: center;
  padding: var(--space-4) var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
  text-align: center;
}

.certificate-steps > div > span {
  display: grid;
  width: 36px;
  height: 36px;
  flex: 0 0 36px;
  place-items: center;
  margin-bottom: var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: 50%;
  background: var(--bg-surface);
  color: var(--text-muted);
  font: 700 13px var(--font-mono);
}

.certificate-steps > div.complete > span {
  border-color: var(--emerald-border);
  background: var(--emerald-soft);
  color: var(--emerald);
}

.certificate-steps > div > b {
  display: flex;
  min-height: 3em;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-2);
  font-size: 14px;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.certificate-steps > div > small {
  margin-top: auto;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

/* --------------------------------------------------------------------------
   17. CERTIFICATE SYSTEM & PRINT STYLES
   -------------------------------------------------------------------------- */
.certificate-page {
  min-height: 100vh;
  background-color: var(--bg-canvas);
  padding: var(--space-7) var(--space-4);
  display: grid;
  place-items: center;
}

.verification-page {
  min-height: 100vh;
  padding: clamp(24px, 6vw, 72px) 16px;
  background: var(--bg-canvas);
  color: var(--text-primary);
}

.verification-container {
  position: relative;
  width: min(720px, 100%);
  margin: 0 auto;
  padding-top: 52px;
}

.verification-theme {
  position: absolute;
  top: 0;
  right: 0;
  width: auto;
  padding-inline: 12px;
  font-size: 12px;
}

.verification-card {
  padding: clamp(28px, 6vw, 48px);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  background: var(--bg-surface);
  box-shadow: var(--shadow-lg);
  text-align: center;
}

.verification-card h1 {
  margin: var(--space-3) 0 var(--space-4);
  font-size: clamp(24px, 5vw, 34px);
}

.verification-card h2 {
  margin: var(--space-2) 0 var(--space-3);
  overflow-wrap: anywhere;
  font-size: clamp(22px, 5vw, 30px);
}

.verification-card h3 {
  margin: var(--space-2) 0 var(--space-4);
  color: var(--cyan);
  font-size: 19px;
}

.verification-card p {
  color: var(--text-secondary);
  line-height: 1.65;
}

.verification-status {
  display: inline-flex;
  margin: 0 auto var(--space-4);
  padding: 5px 12px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  font: 700 11px var(--font-mono);
  letter-spacing: 0.08em;
}

.verification-status.valid {
  border-color: var(--emerald-border);
  background: var(--emerald-soft);
  color: var(--emerald);
}

.verification-status.invalid {
  border-color: var(--rose-border);
  background: var(--rose-soft);
  color: var(--danger);
}

.verification-date,
.verification-id-label,
.verification-disclaimer {
  font-size: 12px;
}

.verification-card hr {
  margin: var(--space-6) 0;
  border: 0;
  border-top: 1px solid var(--border-hairline);
}

.verification-id-label {
  margin-bottom: var(--space-1);
  font: 700 10px var(--font-mono);
  letter-spacing: 0.12em;
  color: var(--text-muted) !important;
}

.verification-id {
  color: var(--cyan);
  font: 700 15px var(--font-mono);
  letter-spacing: 0.12em;
  overflow-wrap: anywhere;
}

.verification-share-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-2);
  margin: var(--space-5) 0 var(--space-2);
}

.verification-copy-status {
  min-height: 1.5em;
  margin: 0;
  font-size: 12px;
}

.certificate-copy-status {
  min-height: 1.5em;
  margin: 0;
  color: var(--text-secondary);
  font-size: 12px;
  text-align: center;
}

.verification-correction-note {
  padding: var(--space-3);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
  font-size: 12px;
}

.certificate-linkedin-guide {
  margin-top: var(--space-4);
  padding: var(--space-4);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
  color: var(--text-secondary);
  font-size: 12px;
  line-height: 1.65;
}

.certificate-linkedin-guide summary {
  color: var(--text-primary);
  font-weight: 700;
  cursor: pointer;
}

.certificate-linkedin-guide ol {
  display: grid;
  gap: var(--space-2);
  padding-left: var(--space-5);
  margin: var(--space-3) 0 0;
}

.certificate-linkedin-guide li {
  overflow-wrap: anywhere;
}

.verification-home {
  margin-top: var(--space-6);
}

.verification-home a {
  color: var(--cyan);
  font-weight: 600;
}

.verification-disclaimer {
  margin: var(--space-4) 0 0;
  color: var(--text-muted) !important;
}

.certificate-container {
  width: min(1000px, 100%);
}

.certificate-sheet {
  width: 100%;
  background-color: var(--cert-sheet-bg);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: var(--space-4);
}

.certificate-inner {
  border: 2px solid var(--border-default);
  outline: 1px solid var(--cert-border-gold);
  outline-offset: -12px;
  padding: var(--space-8) var(--space-8);
  text-align: center;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: var(--cert-inner-bg);
}

.cert-logo {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 16px;
  letter-spacing: 0.2em;
  color: var(--text-primary);
}

.cert-logo img {
  display: block;
  width: min(170px, 45vw);
  height: auto;
  margin-inline: auto;
}

.cert-logo img.brand-logo-dark {
  display: none;
}

:root:not([data-theme="light"]) .cert-logo img.brand-logo-light,
[data-theme="dark"] .cert-logo img.brand-logo-light {
  display: none;
}

:root:not([data-theme="light"]) .cert-logo img.brand-logo-dark,
[data-theme="dark"] .cert-logo img.brand-logo-dark {
  display: block;
}

.cert-kicker {
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--amber);
  font-weight: 800;
  font-family: var(--font-mono);
  margin-top: var(--space-6);
}

.certificate-inner h1 {
  font-size: clamp(26px, 4vw, 42px);
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin: var(--space-2) 0;
}

.cert-sub {
  font-size: 14px;
  color: var(--text-secondary);
}

.cert-name {
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 700;
  font-size: clamp(24px, 3.5vw, 36px);
  color: var(--cert-name-color);
  border-bottom: 1px solid var(--cert-border-gold);
  padding: var(--space-3) var(--space-7) var(--space-2);
  margin: var(--space-4) 0;
  min-width: 50%;
  word-break: break-word;
}

.cert-course {
  font-size: 20px;
  color: var(--text-primary);
  margin: var(--space-1) 0 var(--space-3);
}

.cert-text {
  max-width: 620px;
  color: var(--text-secondary);
  font-size: 12px;
  line-height: 1.7;
}

.cert-meta {
  display: flex;
  justify-content: space-between;
  gap: var(--space-7);
  width: 85%;
  margin-top: var(--space-7);
  border-top: 1px solid var(--border-hairline);
  padding-top: var(--space-4);
  text-align: left;
}

.cert-meta b {
  font-size: 10px;
  color: var(--text-muted);
  display: block;
  letter-spacing: 0.06em;
  font-family: var(--font-mono);
}

.cert-meta small {
  font-size: 11px;
  color: var(--text-primary);
  display: block;
  margin-top: 2px;
}

.cert-id {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.1em;
}

.cert-disclaimer {
  font-size: 9px;
  color: var(--text-muted);
  margin-top: var(--space-5);
}

.certificate-actions {
  display: flex;
  justify-content: center;
  gap: var(--space-3);
  margin-top: var(--space-5);
  flex-wrap: wrap;
}

.certificate-error {
  max-width: 600px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  padding: var(--space-6);
  border-radius: var(--radius-md);
  text-align: center;
  margin: 0 auto;
}

@media print {
  @page {
    size: A4 landscape;
    margin: 8mm;
  }
  body, .certificate-page {
    background: #ffffff !important;
    color: #000000 !important;
    padding: 0 !important;
  }
  .certificate-sheet {
    box-shadow: none !important;
    border: none !important;
    padding: 0 !important;
    width: 100% !important;
    background: #ffffff !important;
  }
  .certificate-inner {
    background: #ffffff !important;
    border: 3px double #000000 !important;
    outline: 1px solid #78350f !important;
  }
  .cert-logo, .certificate-inner h1, .cert-course, .cert-name {
    color: #000000 !important;
  }
  .cert-logo img {
    display: none !important;
  }
  .cert-logo .brand-logo-light {
    display: block !important;
  }
  .cert-sub, .cert-text, .cert-meta small, .cert-disclaimer {
    color: #374151 !important;
  }
  .certificate-actions {
    display: none !important;
  }
}

/* --------------------------------------------------------------------------
   18. TOAST NOTIFICATIONS & LEGAL VIEWS
   -------------------------------------------------------------------------- */
.toast {
  position: fixed;
  right: var(--space-5);
  bottom: var(--space-5);
  z-index: 100;
  max-width: min(400px, calc(100% - 32px));
  padding: var(--space-3) var(--space-4);
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-default);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  font-size: 13px;
  font-weight: 500;
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: opacity 150ms ease, transform 150ms ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.toast.success {
  border-left: 4px solid var(--emerald);
}

.toast.error {
  border-left: 4px solid var(--rose);
}

.legal-wrap {
  max-width: var(--container-narrow);
  margin: var(--space-8) auto;
  padding: 0 var(--space-4) var(--space-9);
}

.legal-wrap h1 {
  font-size: 32px;
  margin: var(--space-2) 0 var(--space-4);
  letter-spacing: -0.025em;
}

.legal-wrap h2 {
  font-size: 18px;
  margin: var(--space-7) 0 var(--space-2);
  letter-spacing: -0.015em;
}

.legal-wrap p, .legal-wrap li {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.legal-wrap p {
  margin: var(--space-2) 0 var(--space-3);
}

.legal-wrap .legal-date {
  color: var(--text-muted);
  font-size: 13px;
  margin-bottom: var(--space-5);
}

.legal-wrap ul {
  padding-left: var(--space-5);
  margin: var(--space-3) 0 var(--space-5);
}

.legal-wrap li {
  margin-bottom: var(--space-2);
}

.legal-wrap .brand {
  margin-bottom: var(--space-6);
  display: inline-flex;
}

.legal-wrap .back-home {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-6);
  font-weight: 600;
  font-size: 13px;
  color: var(--cyan);
  transition: color 150ms ease, transform 150ms ease;
}

.legal-wrap .back-home:hover {
  color: var(--cyan-hover);
  transform: translateX(-2px);
}

.hidden {
  display: none !important;
}

/* --------------------------------------------------------------------------
   19. RESPONSIVE MEDIA QUERIES (COMPREHENSIVE MULTI-DEVICE CALIBRATION)
   -------------------------------------------------------------------------- */
@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  .certificate-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .capstone-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  .steps-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .step-card:last-child {
    grid-column: 1 / -1;
    max-width: 480px;
    justify-self: center;
    width: 100%;
  }
}

@media (max-width: 768px) {
  :root {
    --topbar-height: 56px;
  }
  .nav-links, .nav-cta {
    display: none;
  }
  .nav {
    justify-content: space-between;
  }
  .nav .brand {
    width: min(166px, 48vw);
  }
  .footer-brand .brand {
    width: min(184px, 60vw);
  }
  .mobile-nav-group {
    display: flex;
  }
  .mobile-menu {
    display: block;
  }
  .section {
    padding: var(--space-7) 0;
  }
  .section-heading {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }
  .program-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  .faq-grid {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }
  .auth-card {
    grid-template-columns: 1fr;
    max-width: 440px;
    margin: 0 auto;
  }
  .auth-side {
    padding: var(--space-5);
    border-right: none;
    border-bottom: 1px solid var(--border-hairline);
  }
  .auth-form-side {
    padding: var(--space-5);
  }
  .lesson-study-body {
    grid-template-columns: 1fr;
    padding: var(--space-3);
  }
  .lesson-video-caption {
    padding: var(--space-3);
  }
  .lesson-video-chapters {
    grid-template-columns: 1fr;
  }
  .quiz-form .choice-list {
    grid-template-columns: 1fr;
  }
  .cta-inner {
    flex-direction: column;
    align-items: flex-start;
  }
  .cta-actions {
    width: 100%;
  }
  .cta-actions .btn {
    width: 100%;
  }
  .footer-main {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-5);
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
    gap: var(--space-2);
  }
  .admin-stats {
    grid-template-columns: 1fr 1fr;
  }
  .trust-inner {
    justify-content: center;
    gap: var(--space-3);
    padding: var(--space-3) 0;
    text-align: center;
  }
  .trust-inner i {
    display: none;
  }
}

@media (max-width: 640px) {
  .certificate-page {
    padding: var(--space-4) var(--space-2);
  }
  .certificate-sheet {
    padding: var(--space-2);
  }
  .certificate-inner {
    padding: var(--space-5) var(--space-3);
    outline-offset: -8px;
  }
  .cert-name {
    min-width: 0;
    width: 100%;
    padding: var(--space-2) var(--space-2);
    font-size: 22px;
  }
  .cert-meta {
    width: 100%;
    flex-direction: column;
    gap: var(--space-3);
    text-align: center;
  }
  .certificate-actions {
    flex-direction: column;
    width: 100%;
  }
  .certificate-actions .btn {
    width: 100%;
  }
}

@media (max-width: 560px) {
  .container, .container.narrow {
    width: calc(100% - 24px);
  }
  .certificate-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .certificate-steps > div {
    min-height: 170px;
  }
  .hero {
    padding: var(--space-7) 0;
  }
  .hero h1 {
    font-size: clamp(28px, 8vw, 36px);
  }
  .hero-lead {
    font-size: 14px;
    margin-bottom: var(--space-4);
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .hero-proof {
    margin-top: var(--space-5);
    padding-top: var(--space-4);
    flex-wrap: wrap;
  }
  .code-window pre {
    padding: var(--space-3) var(--space-3);
    font-size: 11px;
    line-height: 1.75;
  }
  .code-status {
    font-size: 10px;
    padding: var(--space-2) var(--space-3);
    flex-wrap: wrap;
  }
  .steps-grid {
    grid-template-columns: 1fr;
  }
  .step-card:last-child {
    max-width: none;
  }
  .admin-stats {
    grid-template-columns: 1fr;
  }
  .architecture-card {
    padding: var(--space-4);
  }
  .arch-row {
    flex-direction: column;
    gap: var(--space-2);
  }
  .arch-foot {
    flex-direction: column;
    gap: var(--space-1);
    text-align: center;
  }
  .toast {
    inset-inline: var(--space-3);
    right: auto;
    left: auto;
    width: calc(100% - 24px);
    max-width: none;
    bottom: var(--space-3);
    text-align: center;
  }
  /* Mobile player controls adjustments */
  .lesson-theater-button {
    display: none !important;
  }
  .lesson-volume input[type="range"] {
    display: none !important;
  }
  .lesson-play-button {
    flex: 1 1 auto;
    min-width: 0;
    padding: 0 var(--space-2);
    font-size: 12px;
  }
  .lesson-player-time {
    font-size: 10px;
  }
  .question {
    padding: var(--space-4) var(--space-3);
  }
  .written-evidence {
    padding: var(--space-4) var(--space-3);
  }
  .legal-wrap {
    margin: var(--space-5) auto;
    padding: 0 var(--space-3) var(--space-6);
  }
}

@media (max-width: 380px) {
  .certificate-steps {
    grid-template-columns: 1fr;
  }
  .certificate-steps > div {
    min-height: 150px;
  }
  .lesson-icon-button {
    width: 30px;
    height: 30px;
  }
  .lesson-play-button {
    height: 30px;
    font-size: 11px;
  }
  .lesson-speed select {
    height: 30px;
    font-size: 11px;
  }
  .lesson-volume-button {
    width: 30px;
    height: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}

.certificate-lookup-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.85fr);
  align-items: center;
  gap: clamp(24px, 5vw, 64px);
}

.certificate-lookup-inner h2 {
  margin: 8px 0;
}

.certificate-lookup-inner p {
  max-width: 520px;
  color: var(--text-muted);
}

.certificate-lookup-form {
  display: grid;
  gap: 8px;
  padding: 22px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  background: var(--bg-surface);
  box-shadow: var(--shadow-sm);
}

.certificate-lookup-form > label {
  font-weight: 700;
  font-size: 13px;
}

.certificate-lookup-form > div {
  display: flex;
  gap: 10px;
}

.certificate-lookup-form input {
  width: 100%;
  min-width: 0;
  min-height: 46px;
  padding: 10px 12px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-canvas);
  color: var(--text-primary);
  font: 13px var(--font-mono);
}

.certificate-lookup-form small {
  color: var(--text-muted);
  font-size: 11px;
}

@media (max-width: 720px) {
  .certificate-lookup-inner {
    grid-template-columns: 1fr;
  }

  .certificate-lookup-form > div {
    flex-direction: column;
  }
}