:root {
  --navy: #0d1b2e;
  --navy-deep: #091320;
  --panel: #142944;
  --panel-2: #182f4d;
  --border: #24405f;
  --ink: #eef4fb;
  --muted: #a9bdd4;
  --muted-2: #7e93ab;
  --blue: #38bdf8;
  --blue-bright: #7dd3fc;
  --blue-deep: #0ea5e9;
  --radius: 14px;
  --serif: "Lora", Georgia, serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--navy);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.2;
  margin: 0 0 0.5em;
}

a { color: inherit; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(9, 19, 32, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  text-decoration: none;
  font-size: 0.85rem;
  letter-spacing: 0.01em;
  color: var(--ink);
  min-width: 0;
  flex: 1 1 auto;
  margin-right: 20px;
}

.brand-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand-mark {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--blue);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.18);
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 0.9rem;
  font-weight: 500;
  flex-shrink: 0;
}

.site-nav a {
  text-decoration: none;
  color: var(--muted);
  transition: color 0.15s ease;
}

.site-nav a:hover { color: var(--ink); }

.nav-cta {
  color: var(--navy) !important;
  background: var(--blue);
  padding: 9px 16px;
  border-radius: 999px;
  font-weight: 600;
}

.nav-cta:hover { background: var(--blue-bright); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  padding: 8px;
  cursor: pointer;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
}

/* Hero */
.hero {
  padding: 72px 0 56px;
  background:
    radial-gradient(1200px 480px at 15% -10%, rgba(56, 189, 248, 0.14), transparent 60%),
    var(--navy);
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--blue);
  margin: 0 0 14px;
}

.hero h1 {
  font-size: clamp(2.1rem, 4.2vw, 3.1rem);
  margin-bottom: 0.35em;
}

.hero-sub {
  font-size: 1.08rem;
  color: var(--muted);
  max-width: 46ch;
  margin: 0 0 28px;
}

.hero-stats {
  list-style: none;
  display: flex;
  gap: 28px;
  padding: 0;
  margin: 0 0 32px;
  flex-wrap: wrap;
}

.hero-stats li {
  display: flex;
  flex-direction: column;
}

.hero-stats strong {
  font-family: var(--serif);
  font-size: 1.6rem;
  color: var(--blue-bright);
  line-height: 1.1;
}

.hero-stats span {
  font-size: 0.78rem;
  color: var(--muted-2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.cta-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.cta-row-center { justify-content: center; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.96rem;
  text-decoration: none;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--blue);
  color: var(--navy-deep);
  box-shadow: 0 8px 24px -8px rgba(56, 189, 248, 0.55);
}

.btn-primary:hover { background: var(--blue-bright); transform: translateY(-1px); }

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

.btn-secondary:hover { border-color: var(--blue); color: var(--blue-bright); transform: translateY(-1px); }

.hero-note {
  margin: 16px 0 0;
  font-size: 0.85rem;
  color: var(--muted-2);
}

.hero-cover {
  display: flex;
  justify-content: center;
}

.hero-cover img {
  width: 100%;
  max-width: 360px;
  height: auto;
  aspect-ratio: 720 / 1152;
  border-radius: 10px;
  box-shadow: 0 30px 60px -20px rgba(0, 0, 0, 0.6), 0 0 0 1px var(--border);
}

/* Sections */
.section { padding: 84px 0; }

.section h2 {
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  text-align: center;
}

.section-sub {
  text-align: center;
  color: var(--muted);
  max-width: 56ch;
  margin: 0 auto 48px;
}

/* Premise */
.premise { padding-top: 64px; }

.premise-inner { max-width: 880px; }

.lede {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.25rem;
  color: var(--ink);
  text-align: center;
  max-width: 68ch;
  margin: 0 auto 48px;
  line-height: 1.55;
}

.format-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 28px;
}

.format-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.format-card p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.format-card strong { color: var(--ink); }

.level-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  border-radius: 999px;
}

.level-junior { background: rgba(56, 189, 248, 0.14); color: var(--blue-bright); }
.level-senior { background: rgba(129, 140, 248, 0.16); color: #a5b4fc; }
.level-staff { background: rgba(244, 114, 182, 0.14); color: #f9a8d4; }

.premise-note {
  text-align: center;
  color: var(--muted-2);
  font-size: 0.92rem;
  max-width: 62ch;
  margin: 0 auto;
}

/* Who it's for */
.who { background: var(--navy-deep); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.who-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.who-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
}

.who-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.4em;
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
}

.who-card p {
  color: var(--muted);
  font-size: 0.94rem;
  margin: 0;
}

/* Inside the book */
.chapter-list {
  list-style: none;
  padding: 0;
  margin: 0 0 40px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0 32px;
  counter-reset: none;
}

.chapter-list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--border);
}

.ch-num {
  font-family: var(--serif);
  color: var(--blue);
  font-size: 0.85rem;
  flex-shrink: 0;
  width: 22px;
}

.ch-title { color: var(--ink); font-size: 0.96rem; }

/* Sample Q&A */
.sample { background: var(--navy-deep); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.qa-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.qa-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex;
  flex-direction: column;
}

.qa-card .level-tag { margin-bottom: 16px; }

.qa-q {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.08rem;
  color: var(--ink);
  margin: 0 0 16px;
}

.qa-a {
  font-size: 0.9rem;
  color: var(--muted);
  margin: 0;
}

/* Buy */
.buy { text-align: center; }

.buy-inner { max-width: 640px; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
}

.footer-inner {
  text-align: center;
  color: var(--muted-2);
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 1000px) {
  .qa-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 860px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-cover { order: -1; max-width: 260px; margin: 0 auto; }
  .format-grid, .who-grid { grid-template-columns: 1fr; }
  .qa-grid { grid-template-columns: 1fr; }
  .chapter-list { grid-template-columns: 1fr; }

  .site-nav {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--navy-deep);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 8px 24px 20px;
    display: none;
  }

  .site-nav.open { display: flex; }
  .site-nav a { padding: 12px 0; width: 100%; }
  .nav-cta { margin-top: 8px; text-align: center; }
  .nav-toggle { display: flex; }
}

@media (max-width: 520px) {
  .hero-stats { gap: 20px; }
  .section { padding: 56px 0; }
}