:root {
  --navy-dark: #0a0e1a;
  --navy-mid: #0f1424;
  --navy-card: #131b33;
  --navy-light: #1a2545;
  --navy-border: #1e2d50;
  --gold: #d4a853;
  --gold-light: #e8c97a;
  --gold-glow: rgba(212, 168, 83, 0.15);
  --white: #f0f2f5;
  --text-body: #b0b8cc;
  --text-muted: #6b7394;
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--navy-dark);
  color: var(--text-body);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--gold); text-decoration: none; transition: opacity .2s; }
a:hover { opacity: .75; }

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

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

.section-label {
  display: inline-block;
  font-size: .75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2.5px;
  color: var(--gold);
  margin-bottom: 16px;
}

h1, h2, h3, h4 {
  color: var(--white);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2rem, 5vw, 3.2rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin-bottom: 16px; }
h3 { font-size: 1.15rem; margin-bottom: 10px; }
h4 { font-size: 1rem; }

p { margin-bottom: 12px; color: var(--text-body); }
p:last-child { margin-bottom: 0; }

/* ── Buttons ─────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-weight: 600;
  font-size: .9rem;
  cursor: pointer;
  border: none;
  transition: all .25s;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--gold), var(--gold-light));
  color: var(--navy-dark);
}

.btn-primary:hover { opacity: .9; transform: translateY(-1px); box-shadow: 0 8px 24px var(--gold-glow); }

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--gold);
  color: var(--gold);
}

.btn-outline:hover { background: var(--gold-glow); }

.btn-pulse { animation: pulse 2s infinite; }

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--gold-glow); }
  50% { box-shadow: 0 0 0 12px transparent; }
}

/* ── Navbar ───────────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: all .3s;
  background: transparent;
}

.navbar.scrolled {
  background: rgba(10, 14, 26, .92);
  backdrop-filter: blur(16px);
  padding: 10px 0;
  border-bottom: 1px solid rgba(212, 168, 83, .08);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-brand {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.03em;
}

.navbar-brand span { color: var(--gold); }

.nav-links { display: flex; gap: 28px; list-style: none; align-items: center; }

.nav-links a {
  color: var(--text-body);
  font-size: .85rem;
  font-weight: 500;
  transition: color .2s;
  position: relative;
}

.nav-links a:hover,
.nav-links a.active { color: var(--gold); }

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0; right: 0;
  height: 2px;
  background: var(--gold);
  border-radius: 1px;
}

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

.mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: all .3s;
}

/* ── Hero ─────────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 60px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at center, rgba(212, 168, 83, .03) 0%, transparent 60%);
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% { transform: translate(0, 0); }
  100% { transform: translate(-5%, 5%); }
}

.hero-content { position: relative; z-index: 1; max-width: 800px; }

.hero-content h1 { margin-bottom: 20px; }

.hero-content p {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 36px;
}

.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

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

.page-hero {
  padding: 140px 24px 60px;
  text-align: center;
  background: linear-gradient(180deg, rgba(212, 168, 83, .04) 0%, transparent 100%);
}

.page-hero h1 { margin-bottom: 12px; }
.page-hero p { color: var(--text-muted); max-width: 600px; margin: 0 auto; }

/* ── Cards ────────────────────────────────────────────────────── */
.card {
  background: linear-gradient(135deg, var(--navy-card), var(--navy-light));
  border: 1px solid var(--navy-border);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: all .3s;
}

.card:hover { border-color: var(--gold); transform: translateY(-3px); }

/* ── Chapter Accordion ───────────────────────────────────────── */
.chapter-list { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }

.chapter-item {
  background: var(--navy-card);
  border: 1px solid var(--navy-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color .3s;
}

.chapter-item.open { border-color: var(--gold); }

.chapter-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 24px;
  cursor: pointer;
  user-select: none;
  transition: background .2s;
}

.chapter-header:hover { background: rgba(255, 255, 255, .02); }

.chapter-number {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-weight: 700;
  font-size: .85rem;
  flex-shrink: 0;
}

.chapter-number.unlocked { background: var(--gold-glow); color: var(--gold); }
.chapter-number.locked { background: rgba(255, 255, 255, .05); color: var(--text-muted); }

.chapter-info { flex: 1; }
.chapter-info h3 { font-size: .95rem; margin-bottom: 2px; }
.chapter-info p { font-size: .8rem; color: var(--text-muted); }

.chapter-status { font-size: .75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; }
.chapter-status.unlocked { color: #4ade80; }
.chapter-status.locked { color: var(--text-muted); }

.chapter-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height .4s ease, padding .4s ease;
}

.chapter-item.open .chapter-body {
  max-height: 200px;
  padding: 0 24px 20px;
}

.chapter-body p { font-size: .85rem; margin-bottom: 12px; }
.chapter-body a { font-size: .85rem; font-weight: 600; }

/* ── Takeaway cards ──────────────────────────────────────────── */
.takeaway {
  background: rgba(212, 168, 83, .06);
  border-left: 3px solid var(--gold);
  padding: 20px 24px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
}

.takeaway p { font-size: .9rem; color: var(--gold-light); margin-bottom: 4px; }
.takeaway p:last-child { margin-bottom: 0; }

.takeaway strong { color: var(--white); }

/* ── Content layout ──────────────────────────────────────────── */
.content-section { padding: 60px 0; }
.content-section .container { max-width: 800px; }

.content-section h2 {
  margin-top: 40px;
  margin-bottom: 16px;
}

.content-section h3 { margin-top: 28px; margin-bottom: 10px; }

.content-section ul, .content-section ol {
  margin: 16px 0 24px 24px;
}

.content-section li { margin-bottom: 8px; }

/* ── Chapter nav ─────────────────────────────────────────────── */
.chapter-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--navy-border);
}

.chapter-nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: .9rem;
  font-weight: 600;
}

/* ── Footer ───────────────────────────────────────────────────── */
.footer {
  background: var(--navy-mid);
  border-top: 1px solid var(--navy-border);
  padding: 60px 0 30px;
  margin-top: 60px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer h3 { font-size: 1.1rem; margin-bottom: 16px; }
.footer h3 span { color: var(--gold); }
.footer h4 { font-size: .85rem; text-transform: uppercase; letter-spacing: 1.5px; color: var(--text-muted); margin-bottom: 16px; }
.footer ul { list-style: none; }
.footer ul li { margin-bottom: 8px; }
.footer ul a { font-size: .85rem; color: var(--text-body); }
.footer p { font-size: .85rem; }

.footer-bottom {
  border-top: 1px solid var(--navy-border);
  padding-top: 24px;
  text-align: center;
}

.footer-bottom p { font-size: .8rem; color: var(--text-muted); }

/* ── Animations ───────────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in { animation: fadeUp .6s ease forwards; }

/* ── Responsive ───────────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0; right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--navy-card);
    flex-direction: column;
    padding: 80px 32px 32px;
    gap: 20px;
    transition: right .3s;
    border-left: 1px solid var(--navy-border);
  }

  .nav-links.open { right: 0; }

  .mobile-toggle { display: flex; }

  .footer-grid { grid-template-columns: 1fr; gap: 32px; }

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

  .chapter-nav { flex-direction: column; align-items: center; }

  .chapter-header { padding: 16px; }
  .chapter-number { width: 32px; height: 32px; font-size: .75rem; }
}