/* ==========================================================================
   LES OBJECTIONS, C'EST SIMPLE · Design System Système1-Immo™
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Geist:wght@300;400;500;600;700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ==========================================================================
   DESIGN TOKENS
   ========================================================================== */

:root {
  /* Colors */
  --navy-950: #070B14;
  --navy-900: #0A0F1C;
  --navy-800: #0F1523;
  --navy-700: #151C2E;
  --navy-600: #1F2940;
  --navy-500: #2A3656;

  --accent-blue: #5BA3E8;
  --accent-blue-dark: #3A7FC2;
  --accent-blue-light: #8BC0F0;

  --accent-purple: #A78BFA;
  --accent-purple-dark: #8B6BDB;
  --accent-purple-light: #C4B0FC;

  --success: #52C77A;
  --warning: #F5B64C;
  --danger: #E85C5C;

  --text-primary: #F5F7FB;
  --text-secondary: #A8B0C0;
  --text-tertiary: #6B7689;
  --text-muted: #4A5265;

  --border-subtle: rgba(91, 163, 232, 0.08);
  --border-default: rgba(91, 163, 232, 0.15);
  --border-strong: rgba(91, 163, 232, 0.30);

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--accent-blue) 0%, var(--accent-purple) 100%);
  --gradient-card: linear-gradient(180deg, rgba(91, 163, 232, 0.04) 0%, rgba(167, 139, 250, 0.02) 100%);
  --gradient-hero: radial-gradient(ellipse at top, rgba(91, 163, 232, 0.15) 0%, transparent 50%);

  /* Typography */
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'Geist', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.45);
  --shadow-glow-blue: 0 0 40px rgba(91, 163, 232, 0.25);
  --shadow-glow-purple: 0 0 40px rgba(167, 139, 250, 0.25);

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

/* ==========================================================================
   RESET & BASE
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--navy-950);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(91, 163, 232, 0.12), transparent),
    radial-gradient(ellipse 60% 50% at 100% 100%, rgba(167, 139, 250, 0.08), transparent);
  pointer-events: none;
  z-index: 0;
}

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

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-blue-light);
}

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

/* ==========================================================================
   TYPOGRAPHY
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

h1 {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  line-height: 1.15;
}

h3 {
  font-size: clamp(1.375rem, 2.5vw, 1.75rem);
}

h4 {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
}

p {
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

strong {
  color: var(--text-primary);
  font-weight: 600;
}

em {
  color: var(--accent-blue-light);
  font-style: normal;
  font-weight: 500;
}

/* ==========================================================================
   LAYOUT
   ========================================================================== */

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

.container-narrow {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

.container-wide {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

main {
  padding: 2rem 0 4rem;
  position: relative;
  z-index: 1;
}

section {
  margin-bottom: 4rem;
}

/* ==========================================================================
   HEADER & NAV
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(7, 11, 20, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 1rem 0;
}

.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--gradient-primary);
  display: grid;
  place-items: center;
  color: white;
  font-weight: 700;
  font-size: 0.875rem;
  box-shadow: var(--shadow-glow-blue);
}

.brand-tag {
  font-size: 0.6875rem;
  color: var(--text-tertiary);
  font-weight: 400;
  margin-left: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
}

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

.progress-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width var(--transition-slow);
}

/* ==========================================================================
   HERO
   ========================================================================== */

.hero {
  position: relative;
  padding: 5rem 0 3rem;
  text-align: center;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  pointer-events: none;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(91, 163, 232, 0.08);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--accent-blue-light);
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 2rem;
}

.hero-eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 10px var(--success);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.3); }
}

.hero-title {
  margin-bottom: 1.5rem;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-accent {
  /* Hérite du gradient parent · plus d'override couleur unie */
  color: inherit;
  -webkit-text-fill-color: inherit;
}

/* ==========================================================================
   BUTTONS
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.9375rem;
  letter-spacing: -0.01em;
  transition: all var(--transition-base);
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 8px 24px rgba(91, 163, 232, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(91, 163, 232, 0.5);
  color: white;
}

.btn-secondary {
  background: var(--navy-800);
  color: var(--text-primary);
  border-color: var(--border-default);
}

.btn-secondary:hover {
  background: var(--navy-700);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.btn-ghost {
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
}

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

.btn-lg {
  padding: 1.125rem 2.25rem;
  font-size: 1.0625rem;
}

.btn-arrow::after {
  content: '→';
  transition: transform var(--transition-base);
}

.btn-arrow:hover::after {
  transform: translateX(4px);
}

/* ==========================================================================
   CARDS
   ========================================================================== */

.card {
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-card);
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.card:hover {
  border-color: var(--border-default);
  transform: translateY(-2px);
}

.card:hover::before {
  opacity: 1;
}

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

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  font-family: var(--font-display);
  color: var(--text-primary);
}

.card-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: rgba(91, 163, 232, 0.12);
  display: grid;
  place-items: center;
  margin-bottom: 1rem;
  color: var(--accent-blue);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.card-grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.card-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.card-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

@media (max-width: 768px) {
  .card-grid-2, .card-grid-3, .card-grid-4 {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   CALLOUTS
   ========================================================================== */

.callout {
  border-left: 3px solid var(--accent-blue);
  background: rgba(91, 163, 232, 0.05);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0;
}

.callout-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-blue);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
  display: block;
}

.callout-purple {
  border-left-color: var(--accent-purple);
  background: rgba(167, 139, 250, 0.05);
}

.callout-purple .callout-label {
  color: var(--accent-purple);
}

.callout-success {
  border-left-color: var(--success);
  background: rgba(82, 199, 122, 0.05);
}

.callout-success .callout-label {
  color: var(--success);
}

.callout-warning {
  border-left-color: var(--warning);
  background: rgba(245, 182, 76, 0.05);
}

.callout-warning .callout-label {
  color: var(--warning);
}

/* ==========================================================================
   PRINCIPLE BOX
   ========================================================================== */

.principle {
  background: linear-gradient(135deg, rgba(91, 163, 232, 0.1) 0%, rgba(167, 139, 250, 0.06) 100%);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: 1.75rem 2rem;
  margin: 2rem 0;
  position: relative;
}

.principle-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-purple-light);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 0.75rem;
}

.principle-text {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 500;
  line-height: 1.5;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

/* ==========================================================================
   DIALOGUE / SCRIPT
   ========================================================================== */

.script {
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: 1.5rem 0;
}

.script-role {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-blue);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}

.script-role.agent {
  color: var(--accent-purple);
}

.script-line {
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--text-primary);
  font-style: italic;
  position: relative;
  padding-left: 1rem;
}

.script-line::before {
  content: '«';
  position: absolute;
  left: 0;
  color: var(--accent-blue);
  font-family: var(--font-display);
  font-size: 1.5rem;
  line-height: 1;
}

.script-line::after {
  content: ' »';
  color: var(--accent-blue);
}

.script + .script {
  margin-top: 0.75rem;
}

.script-note {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin-top: 0.75rem;
  font-family: var(--font-mono);
}

/* ==========================================================================
   TABLE
   ========================================================================== */

.table-wrap {
  overflow-x: auto;
  margin: 1.5rem 0;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--navy-800);
}

th, td {
  padding: 1rem 1.25rem;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.9375rem;
}

th {
  background: var(--navy-700);
  color: var(--text-primary);
  font-weight: 600;
  font-family: var(--font-display);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

td {
  color: var(--text-secondary);
  vertical-align: top;
}

td strong {
  color: var(--text-primary);
}

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

/* ==========================================================================
   STEP LIST
   ========================================================================== */

.steps {
  list-style: none;
  counter-reset: step;
  margin: 2rem 0;
}

.step {
  position: relative;
  padding: 0 0 2rem 3.5rem;
  counter-increment: step;
}

.step:not(:last-child)::after {
  content: '';
  position: absolute;
  left: 1.125rem;
  top: 2.5rem;
  bottom: 0;
  width: 1px;
  background: var(--border-default);
}

.step::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: white;
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.9375rem;
  box-shadow: var(--shadow-glow-blue);
}

.step-title {
  font-family: var(--font-display);
  font-size: 1.1875rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.step-desc {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   QUOTE
   ========================================================================== */

.quote-block {
  border-left: 3px solid var(--accent-purple);
  padding: 1rem 0 1rem 2rem;
  margin: 2.5rem 0;
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 500;
  line-height: 1.4;
  color: var(--text-primary);
  font-style: italic;
  letter-spacing: -0.01em;
}

.quote-attr {
  display: block;
  margin-top: 1rem;
  font-size: 0.9375rem;
  color: var(--text-tertiary);
  font-style: normal;
  font-weight: 400;
  font-family: var(--font-body);
}

/* ==========================================================================
   CHAPTER NAVIGATION
   ========================================================================== */

.chapter-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
}

.chapter-nav-item {
  display: flex;
  flex-direction: column;
  padding: 1.25rem 1.5rem;
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  text-decoration: none;
  color: var(--text-primary);
}

.chapter-nav-item:hover {
  border-color: var(--border-default);
  transform: translateY(-2px);
  background: var(--navy-700);
  color: var(--text-primary);
}

.chapter-nav-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.25rem;
}

.chapter-nav-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-primary);
}

.chapter-nav-item.next {
  text-align: right;
}

@media (max-width: 640px) {
  .chapter-nav {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   CHAPTER INTRO
   ========================================================================== */

.chapter-intro {
  padding: 4rem 0 2rem;
  text-align: center;
}

.chapter-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent-blue);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 1rem;
  padding: 0.375rem 0.875rem;
  background: rgba(91, 163, 232, 0.1);
  border-radius: var(--radius-full);
  border: 1px solid var(--border-default);
}

.chapter-title {
  margin-bottom: 1rem;
}

.chapter-lead {
  font-size: 1.1875rem;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ==========================================================================
   FORM (Email Gate)
   ========================================================================== */

.form-group {
  display: flex;
  gap: 0.75rem;
  max-width: 500px;
  margin: 0 auto;
}

.form-input {
  flex: 1;
  padding: 1rem 1.25rem;
  background: var(--navy-800);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(91, 163, 232, 0.15);
}

.form-input::placeholder {
  color: var(--text-tertiary);
}

.form-note {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  text-align: center;
  margin-top: 0.75rem;
}

@media (max-width: 540px) {
  .form-group {
    flex-direction: column;
  }
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

.site-footer {
  margin-top: 6rem;
  padding: 3rem 0 2rem;
  border-top: 1px solid var(--border-subtle);
  text-align: center;
  color: var(--text-tertiary);
  font-size: 0.875rem;
  position: relative;
  z-index: 1;
}

.footer-bio {
  max-width: 600px;
  margin: 0 auto 2rem;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-signature {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text-primary);
  font-size: 1rem;
}

.footer-links {
  margin-top: 1rem;
}

.footer-links a {
  color: var(--text-tertiary);
  margin: 0 0.75rem;
  font-size: 0.875rem;
}

/* ==========================================================================
   UTILITY
   ========================================================================== */

.text-center { text-align: center; }
.text-accent-blue { color: var(--accent-blue); }
.text-accent-purple { color: var(--accent-purple); }
.text-success { color: var(--success); }
.text-muted { color: var(--text-tertiary); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.tag {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  background: rgba(91, 163, 232, 0.1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-blue-light);
  letter-spacing: 0.05em;
}

.tag-purple {
  background: rgba(167, 139, 250, 0.1);
  color: var(--accent-purple-light);
  border-color: rgba(167, 139, 250, 0.3);
}

.divider {
  width: 60px;
  height: 2px;
  background: var(--gradient-primary);
  border: none;
  margin: 2rem auto;
  border-radius: 2px;
}

/* ==========================================================================
   TOC (Summary Page)
   ========================================================================== */

.toc-grid {
  display: grid;
  gap: 1rem;
  margin-top: 3rem;
}

.toc-item {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.5rem 1.75rem;
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--text-primary);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.toc-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--gradient-primary);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform var(--transition-base);
}

.toc-item:hover {
  border-color: var(--border-default);
  transform: translateX(4px);
  background: var(--navy-700);
  color: var(--text-primary);
}

.toc-item:hover::before {
  transform: scaleY(1);
}

.toc-num {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent-blue);
  min-width: 2.5rem;
  letter-spacing: 0.1em;
}

.toc-content {
  flex: 1;
}

.toc-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text-primary);
}

.toc-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.toc-arrow {
  color: var(--text-tertiary);
  font-size: 1.25rem;
  transition: transform var(--transition-base);
}

.toc-item:hover .toc-arrow {
  color: var(--accent-blue);
  transform: translateX(4px);
}

.toc-item.locked {
  opacity: 0.5;
  pointer-events: none;
}

.toc-item.read .toc-num::before {
  content: '✓ ';
  color: var(--success);
}

/* ==========================================================================
   QUIZ
   ========================================================================== */

.quiz-container {
  max-width: 720px;
  margin: 0 auto;
}

.quiz-progress {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
  padding: 1rem 1.25rem;
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}

.quiz-progress-label {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  white-space: nowrap;
}

.quiz-progress-bar {
  flex: 1;
  height: 6px;
  background: var(--navy-700);
  border-radius: 3px;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 3px;
  transition: width var(--transition-slow);
}

.quiz-question {
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
}

.quiz-question-number {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--accent-blue);
  margin-bottom: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 600;
}

.quiz-question-text {
  font-family: var(--font-display);
  font-size: 1.375rem;
  line-height: 1.4;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  font-weight: 500;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.quiz-option {
  display: flex;
  align-items: flex-start;
  gap: 0.875rem;
  padding: 1rem 1.25rem;
  background: var(--navy-700);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
  width: 100%;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.5;
  color: var(--text-secondary);
}

.quiz-option:hover {
  border-color: var(--border-default);
  background: var(--navy-600);
  color: var(--text-primary);
}

.quiz-option.selected {
  border-color: var(--accent-blue);
  background: rgba(91, 163, 232, 0.1);
  color: var(--text-primary);
}

.quiz-option.correct {
  border-color: var(--success);
  background: rgba(82, 199, 122, 0.1);
  color: var(--text-primary);
}

.quiz-option.incorrect {
  border-color: var(--danger);
  background: rgba(232, 92, 92, 0.1);
  color: var(--text-primary);
}

.quiz-option-letter {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--navy-600);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.875rem;
  flex-shrink: 0;
  color: var(--text-tertiary);
}

.quiz-option.selected .quiz-option-letter {
  background: var(--accent-blue);
  color: white;
}

.quiz-option.correct .quiz-option-letter {
  background: var(--success);
  color: white;
}

.quiz-option.incorrect .quiz-option-letter {
  background: var(--danger);
  color: white;
}

.quiz-explanation {
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  background: rgba(91, 163, 232, 0.06);
  border-left: 3px solid var(--accent-blue);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
  display: none;
}

.quiz-explanation.visible {
  display: block;
}

.quiz-result {
  text-align: center;
  padding: 3rem 2rem;
  background: var(--navy-800);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
}

.quiz-result-score {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 5rem);
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
  line-height: 1;
}

.quiz-result-total {
  font-size: 1.125rem;
  color: var(--text-tertiary);
  margin-bottom: 1.5rem;
}

.quiz-result-title {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.quiz-result-msg {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 480px;
  margin: 0 auto 2rem;
}

/* ==========================================================================
   DIPLOMA
   ========================================================================== */

.diploma-container {
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1.5rem;
}

.diploma {
  background: linear-gradient(135deg, #0A0F1C 0%, #151C2E 100%);
  border: 2px solid transparent;
  background-clip: padding-box;
  border-radius: var(--radius-xl);
  padding: 3rem 3rem 2.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg), var(--shadow-glow-blue);
  min-height: 600px;
}

.diploma::before {
  content: '';
  position: absolute;
  inset: 0;
  padding: 2px;
  border-radius: var(--radius-xl);
  background: var(--gradient-primary);
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  -webkit-mask-composite: xor;
  pointer-events: none;
}

.diploma-inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  text-align: center;
  height: 100%;
}

.diploma-header {
  display: flex;
  justify-content: flex-start;
  width: 100%;
  align-items: center;
  padding-right: 120px;
}
@media (max-width: 768px) {
  .diploma-header { padding-right: 90px; }
}

.diploma-brand-block {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-display);
}

.diploma-seal {
  position: absolute;
  top: 2rem;
  right: 2rem;
  width: 100px;
  height: 100px;
  opacity: 0.9;
}

.diploma-body {
  margin: auto 0;
}

.diploma-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--accent-blue);
  text-transform: uppercase;
  letter-spacing: 0.2em;
  margin-bottom: 1rem;
  margin-top: 2rem;
}

.diploma-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 1rem;
  background: linear-gradient(180deg, #FFFFFF 0%, #A8B0C0 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.diploma-certify {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.diploma-name {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 600;
  color: var(--accent-blue-light);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-default);
  display: inline-block;
  min-width: 60%;
}

.diploma-subtitle {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 1.5rem;
  line-height: 1.5;
}

.diploma-footer {
  display: flex;
  justify-content: space-between;
  width: 100%;
  align-items: flex-end;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-subtle);
}

.diploma-signature {
  text-align: left;
}

.diploma-signature-line {
  font-family: 'Brush Script MT', cursive;
  font-size: 1.75rem;
  color: var(--accent-blue-light);
  margin-bottom: 0.25rem;
  line-height: 1;
}

.diploma-signature-name {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-primary);
  font-weight: 600;
}

.diploma-signature-title {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.diploma-date {
  text-align: right;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  letter-spacing: 0.08em;
}

.diploma-date strong {
  display: block;
  color: var(--text-primary);
  font-size: 1rem;
  margin-top: 0.25rem;
}

@media (max-width: 768px) {
  .diploma {
    aspect-ratio: auto;
    padding: 2rem 1.5rem;
  }
}

/* ==========================================================================
   LANDING SPECIFIC
   ========================================================================== */

.landing-proof {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  margin: 3rem 0;
  flex-wrap: wrap;
}

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

.proof-number {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1;
  margin-bottom: 0.375rem;
}

.proof-label {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.landing-features {
  margin: 4rem 0;
}

.landing-cta-final {
  padding: 4rem 2rem;
  text-align: center;
  background: var(--navy-800);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  margin: 3rem 0;
  position: relative;
  overflow: hidden;
}

.landing-cta-final::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center, rgba(91, 163, 232, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

/* ==========================================================================
   SVG DIAGRAM STYLES
   ========================================================================== */

.diagram {
  margin: 2.5rem auto;
  max-width: 640px;
  padding: 2rem;
  background: var(--navy-800);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.diagram svg {
  width: 100%;
  height: auto;
}

.diagram-caption {
  font-size: 0.875rem;
  color: var(--text-tertiary);
  text-align: center;
  margin-top: 1rem;
  font-family: var(--font-mono);
  font-style: normal;
}

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .container, .container-narrow, .container-wide {
    padding: 0 1rem;
  }

  .hero {
    padding: 3rem 0 2rem;
  }

  .landing-proof {
    gap: 1.5rem;
  }

  .proof-number {
    font-size: 2rem;
  }
}

/* ==========================================================================
   PRINT (for diploma)
   ========================================================================== */

@media print {
  body::before { display: none; }
  .site-header, .site-footer, .chapter-nav, .btn { display: none; }
  .diploma { box-shadow: none; border-color: var(--accent-blue); }
}