/* ---- tokens ---- */
:root {
  --bg: #0a1b2e;
  --bg-alt: #0e2238;
  --bg-cta: #112a44;
  --ink: #e9eef5;
  --ink-dim: #a5b4c5;
  --rule: #1d3553;
  --accent: #2dd4bf;          /* teal, matches cover */
  --accent-strong: #14b8a6;
  --accent-soft: rgba(45, 212, 191, 0.12);
  --max: 1120px;
  --max-narrow: 760px;
  --radius: 10px;
  --shadow: 0 25px 60px rgba(0, 0, 0, 0.4);
  --t: 180ms ease;
}

/* ---- base ---- */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img, picture { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; transition: color var(--t); }
a:hover { color: var(--accent-strong); }
h1, h2, h3 { font-family: 'Inter', sans-serif; line-height: 1.15; margin: 0 0 0.6em; }
h1 { font-size: clamp(2.4rem, 6vw, 4.2rem); font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.7rem, 3.5vw, 2.4rem); font-weight: 700; letter-spacing: -0.01em; }
h3 { font-size: 1.15rem; font-weight: 600; letter-spacing: -0.005em; }
p { margin: 0 0 1em; color: var(--ink-dim); }
.section p { font-size: 1.06rem; }
ul { padding-left: 1.2em; }
li { margin-bottom: 0.5em; color: var(--ink-dim); }
li strong { color: var(--ink); font-weight: 600; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.narrow { max-width: var(--max-narrow); }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* ---- top bar ---- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 27, 46, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--rule);
}
.topbar .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { font-weight: 600; color: var(--ink); font-size: 0.95rem; letter-spacing: -0.01em; }
.brand:hover { color: var(--accent); }
.topbar nav { display: flex; gap: 1.5rem; align-items: center; }
.topbar nav a { color: var(--ink-dim); font-size: 0.9rem; font-weight: 500; }
.topbar nav a:hover { color: var(--ink); }
.nav-cta {
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--accent);
  border-radius: 999px;
  color: var(--accent) !important;
}
.nav-cta:hover { background: var(--accent-soft); }

/* ---- hero ---- */
.hero {
  padding: clamp(48px, 8vw, 120px) 0 clamp(64px, 10vw, 140px);
  background:
    radial-gradient(ellipse at top right, rgba(45, 212, 191, 0.08), transparent 60%),
    radial-gradient(ellipse at bottom left, rgba(45, 212, 191, 0.04), transparent 60%),
    var(--bg);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: clamp(40px, 6vw, 80px);
  align-items: center;
}
.eyebrow {
  display: inline-block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin: 0 0 1.5rem;
  padding: 0.3rem 0.7rem;
  background: var(--accent-soft);
  border-radius: 4px;
}
.accent { color: var(--accent); }
.tagline { font-size: 1.4rem; color: var(--ink); margin: 0 0 1.2rem; font-weight: 500; }
.subhead { font-size: 1.1rem; color: var(--ink-dim); margin: 0 0 2rem; max-width: 38em; }
.hero-cta { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ---- buttons ---- */
.btn {
  display: inline-block;
  padding: 0.85rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--t);
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
}
.btn-primary { background: var(--accent); color: #0a1b2e; }
.btn-primary:hover { background: var(--accent-strong); color: #0a1b2e; transform: translateY(-1px); }
.btn-secondary { background: transparent; color: var(--ink); border-color: var(--rule); }
.btn-secondary:hover { color: var(--accent); border-color: var(--accent); }
.btn-outline { background: transparent; color: var(--accent); border-color: var(--accent); }
.btn-outline:hover { background: var(--accent-soft); color: var(--accent); }

/* ---- cover placeholder ---- */
.hero-cover {
  display: flex; justify-content: center; align-items: center;
  perspective: 1200px;
}
.hero-cover img {
  max-width: 360px;
  border-radius: 6px;
  box-shadow: var(--shadow);
  transform: rotateY(-8deg) rotateX(2deg);
  transition: transform 0.5s ease;
}
.hero-cover img:hover { transform: rotateY(0) rotateX(0); }
.cover-placeholder {
  width: 320px; aspect-ratio: 2/3;
  background: linear-gradient(160deg, #0a1b2e 0%, #0e3a40 60%, #14b8a6 100%);
  border-radius: 6px;
  box-shadow: var(--shadow);
  padding: 36px 28px;
  display: flex; flex-direction: column; gap: 18px;
  align-items: center; justify-content: center; text-align: center;
  transform: rotateY(-8deg) rotateX(2deg);
  position: relative;
  overflow: hidden;
}
.cover-placeholder::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(45, 212, 191, 0.2) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(45, 212, 191, 0.2) 1px, transparent 1px);
  background-size: 32px 32px;
  opacity: 0.15;
}
.cover-chip {
  width: 60px; height: 60px; border-radius: 50%;
  border: 2px solid var(--accent);
  display: grid; place-items: center;
  font-weight: 800; color: var(--accent);
  font-size: 1.2rem;
  position: relative; z-index: 1;
}
.cover-title {
  font-weight: 900; font-size: 1.55rem; letter-spacing: -0.01em;
  color: white; line-height: 1.05;
  position: relative; z-index: 1;
}
.cover-with { color: var(--accent); }
.cover-placeholder hr { width: 100px; border: none; border-top: 1px solid rgba(255,255,255,0.4); margin: 0; position: relative; z-index: 1; }
.cover-sub { font-size: 0.78rem; color: white; font-weight: 600; letter-spacing: 0.04em; line-height: 1.3; position: relative; z-index: 1; }
.cover-author { font-size: 0.95rem; color: white; font-weight: 700; letter-spacing: 0.05em; position: relative; z-index: 1; margin-top: 8px; }

/* ---- sections ---- */
.section { padding: clamp(56px, 8vw, 112px) 0; }
.section-alt { background: var(--bg-alt); }
.section-cta { background: var(--bg-cta); border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
.section-lede { color: var(--ink-dim); font-size: 1.06rem; margin: -0.4em 0 2.2rem; }

/* ---- who list ---- */
.who-list { list-style: none; padding: 0; }
.who-list li {
  padding: 1rem 0 1rem 0;
  border-bottom: 1px solid var(--rule);
  margin: 0;
  font-size: 1.06rem;
}
.who-list li:last-child { border-bottom: none; }

/* ---- chapters ---- */
.chapters {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}
.chapter {
  background: var(--bg-alt);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.5rem 1.6rem;
  transition: border-color var(--t), transform var(--t);
}
.chapter:hover { border-color: var(--accent); transform: translateY(-2px); }
.chapter h3 { color: var(--ink); margin-bottom: 0.6em; display: flex; align-items: baseline; gap: 0.8em; }
.ch-num {
  font-family: 'JetBrains Mono', monospace;
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 500;
}
.chapter p { margin: 0; font-size: 0.95rem; line-height: 1.55; }

/* ---- waitlist ---- */
.waitlist-form {
  display: flex; gap: 0.6rem; max-width: 480px; margin: 1.6rem 0 0.8rem;
}
.waitlist-form input {
  flex: 1;
  background: var(--bg);
  color: var(--ink);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--t);
}
.waitlist-form input:focus {
  outline: none;
  border-color: var(--accent);
}
.waitlist-form input::placeholder { color: var(--ink-dim); }
.cta-note { font-size: 0.9rem; color: var(--ink-dim); margin-top: 0.8rem; }

/* ---- footer ---- */
.site-footer {
  padding: 2rem 0;
  border-top: 1px solid var(--rule);
  background: var(--bg-alt);
}
.footer-grid {
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem;
}
.footer-grid p { margin: 0; font-size: 0.88rem; color: var(--ink-dim); }

/* ---- responsive ---- */
@media (max-width: 820px) {
  .hero-grid { grid-template-columns: 1fr; gap: 48px; }
  .hero-cover { order: -1; }
  .cover-placeholder, .hero-cover img { transform: none; }
  .topbar nav { gap: 1rem; }
  .topbar nav a:not(.nav-cta) { display: none; }
  .waitlist-form { flex-direction: column; }
  .waitlist-form input, .waitlist-form button { width: 100%; }
  .footer-grid { justify-content: center; text-align: center; }
}