:root {
  --navy: #16325c;
  --navy-deep: #0c1f38;
  --ink: #1b2a3d;
  --blue: #3d6aa6;
  --sky: #7eb8d8;
  --cyan: #4ec4e8;
  --glow: #9ae7ff;
  --gold: #c4a35a;
  --gold-soft: #e4d0a0;
  --cream: #f6f3ec;
  --ice: #eef5fb;
  --paper: #fbfcfe;
  --muted: #5d6d80;
  --line: rgba(22, 50, 92, 0.12);
  --serif: "Cormorant Garamond", Georgia, serif;
  --sans: "Outfit", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
  --radius: 18px;
  --header: 76px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header);
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-weight: 400;
  line-height: 1.6;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
button, a { -webkit-tap-highlight-color: transparent; }
h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.12; letter-spacing: -0.02em; color: var(--navy); }

.skip-link {
  position: absolute;
  left: 12px;
  top: -40px;
  background: var(--navy);
  color: #fff;
  padding: 8px 12px;
  z-index: 100;
}
.skip-link:focus { top: 12px; }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--gold), var(--cyan));
  z-index: 80;
  box-shadow: 0 0 12px rgba(78, 196, 232, 0.5);
}

.wrap {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.kicker {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--blue);
  margin: 0 0 12px;
}

.idx {
  font-family: var(--mono);
  color: var(--gold);
  margin: 0 0 8px;
  font-size: 0.8rem;
}

.section { padding: 110px 0; position: relative; }

.section-head { max-width: 720px; margin-bottom: 56px; }
.section-head h2 { font-size: clamp(2.1rem, 4.4vw, 3.6rem); margin: 0; }
.section-lead { color: var(--muted); font-size: 1.05rem; max-width: 58ch; }

.ornament {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 18px 0;
  width: 180px;
}
.ornament span {
  flex: 1;
  height: 1px;
  background: var(--gold);
}
.ornament i {
  width: 8px;
  height: 8px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  transition: background 0.35s, box-shadow 0.35s, backdrop-filter 0.35s;
}
.site-header.scrolled {
  background: rgba(251, 252, 254, 0.82);
  backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--line);
}
.header-inner {
  width: min(1180px, calc(100% - 36px));
  margin: 0 auto;
  height: var(--header);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--navy);
  font-weight: 500;
}
.logo-mark {
  width: 34px;
  height: 34px;
  border: 1px solid var(--gold);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: 1.15rem;
  color: var(--navy);
}
.logo-text { font-size: 0.92rem; letter-spacing: 0.04em; }
.nav { display: flex; align-items: center; gap: 28px; }
.nav a {
  text-decoration: none;
  color: var(--navy);
  font-size: 0.9rem;
  font-weight: 400;
  position: relative;
}
.nav a:not(.nav-cta)::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 1px;
  background: var(--gold);
  transition: width 0.3s;
}
.nav a:not(.nav-cta):hover::after,
.nav a.active::after { width: 100%; }
.nav-cta {
  border: 1px solid var(--gold);
  padding: 8px 14px;
  border-radius: 999px;
  color: var(--navy) !important;
}
.menu-btn {
  display: none;
  width: 42px;
  height: 42px;
  border: 0;
  background: none;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
}
.menu-btn span {
  display: block;
  height: 1.5px;
  width: 22px;
  background: var(--navy);
  transition: transform 0.3s, opacity 0.3s;
}
.menu-btn.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.menu-btn.open span:nth-child(2) { opacity: 0; }
.menu-btn.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* Hero */
.hero {
  min-height: 100vh;
  position: relative;
  display: grid;
  place-items: center;
  background:
    radial-gradient(1200px 700px at 80% 20%, rgba(78, 196, 232, 0.18), transparent 55%),
    radial-gradient(900px 600px at 10% 90%, rgba(196, 163, 90, 0.12), transparent 50%),
    linear-gradient(180deg, #f4f8fc 0%, #eaf3fa 48%, #fbfcfe 100%);
  overflow: hidden;
  padding: calc(var(--header) + 20px) 0 80px;
}
#mathCanvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.55;
  z-index: 0;
}
.hero-grid {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(rgba(22, 50, 92, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(22, 50, 92, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at center, #000 30%, transparent 75%);
  pointer-events: none;
}
.hero-inner {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  align-items: center;
  position: relative;
  z-index: 2;
}
.hero h1 {
  font-size: clamp(3.1rem, 7vw, 5.6rem);
  margin: 0;
  color: var(--navy);
}
.hero h1 em {
  font-style: italic;
  background: linear-gradient(180deg, #4a7bb5 0%, #16325c 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.subtitle {
  font-family: var(--serif);
  font-size: 1.45rem;
  color: var(--navy);
  margin: 0 0 18px;
  letter-spacing: 0.08em;
}
.lede {
  color: var(--muted);
  max-width: 46ch;
  font-size: 1.02rem;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin: 28px 0 18px; }
.hero-quote {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.25rem;
  color: var(--navy);
  margin: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  padding: 13px 22px;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 500;
  transition: transform 0.25s, box-shadow 0.25s, background 0.25s;
}
.btn-gold {
  background: linear-gradient(180deg, #d4b76e, var(--gold));
  color: var(--navy-deep);
  box-shadow: 0 10px 24px rgba(196, 163, 90, 0.28);
}
.btn-gold:hover { transform: translateY(-2px); box-shadow: 0 16px 30px rgba(196, 163, 90, 0.38); }
.btn-ghost {
  border: 1px solid var(--navy);
  color: var(--navy);
  background: rgba(255, 255, 255, 0.35);
}
.btn-ghost:hover { transform: translateY(-2px); background: #fff; }

.book-stage {
  perspective: 1400px;
  display: grid;
  place-items: center;
}
.book-img {
  width: min(100%, 460px);
  transform: rotateY(-14deg) rotateX(5deg);
  filter: drop-shadow(28px 42px 36px rgba(12, 31, 56, 0.32));
  animation: bookFloat 5.5s ease-in-out infinite;
  transform-style: preserve-3d;
  will-change: transform;
}
@keyframes bookFloat {
  0%, 100% { transform: rotateY(-14deg) rotateX(5deg) translateY(0); }
  50% { transform: rotateY(-10deg) rotateX(3deg) translateY(-14px); }
}

.scroll-hint {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  text-decoration: none;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  z-index: 2;
}
.scroll-hint b {
  width: 1px;
  height: 36px;
  background: linear-gradient(var(--gold), transparent);
  animation: drip 1.6s ease-in-out infinite;
}
@keyframes drip {
  0% { transform: scaleY(0.4); opacity: 0; }
  40% { opacity: 1; }
  100% { transform: scaleY(1); opacity: 0; }
}

/* Floating equations */
.eq-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  overflow: hidden;
}
.eq-float {
  position: absolute;
  font-family: var(--mono);
  color: rgba(22, 50, 92, 0.18);
  font-size: 0.78rem;
  white-space: nowrap;
  animation: eqDrift linear infinite;
}
@keyframes eqDrift {
  from { transform: translateY(0) rotate(var(--r, 0deg)); opacity: 0; }
  12% { opacity: 1; }
  to { transform: translateY(-110vh) rotate(var(--r, 0deg)); opacity: 0; }
}

.eq-marquee {
  border-block: 1px solid var(--line);
  background: var(--navy-deep);
  color: var(--gold-soft);
  overflow: hidden;
  padding: 14px 0;
}
.eq-track {
  display: flex;
  gap: 42px;
  width: max-content;
  animation: marquee 42s linear infinite;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
}
@keyframes marquee {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* Book section */
.book-section { background: linear-gradient(180deg, #fbfcfe, #f3f7fb); }
.book-layout {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 56px;
  align-items: start;
}
.cover-card {
  margin: 0;
  position: sticky;
  top: calc(var(--header) + 24px);
}
.cover-card img {
  border-radius: 8px 22px 22px 8px;
  box-shadow: 18px 24px 50px rgba(12, 31, 56, 0.18);
}
.cover-card figcaption {
  margin-top: 14px;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}
.book-prose p { font-size: 1.05rem; color: #334155; }
.book-prose blockquote {
  margin: 28px 0;
  padding: 8px 0 8px 22px;
  border-left: 2px solid var(--gold);
  font-family: var(--serif);
  font-size: 1.35rem;
  font-style: italic;
  color: var(--navy);
  line-height: 1.45;
}
.closing {
  font-weight: 500;
  color: var(--navy) !important;
}

/* Inside */
.inside-section {
  background:
    radial-gradient(700px 400px at 100% 0%, rgba(78, 196, 232, 0.1), transparent 50%),
    var(--ice);
}
.anatomy {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-bottom: 28px;
}
.ana-card, .kind, .cred {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  backdrop-filter: blur(8px);
}
.ana-card h3, .kind h3, .cred h3 { margin: 10px 0 8px; font-size: 1.45rem; }
.ana-card p, .kind p, .cred p { margin: 0; color: var(--muted); }
.ana-num {
  font-family: var(--serif);
  color: var(--gold);
  font-size: 1.4rem;
}
.kind-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 22px;
}
.kind {
  transition: transform 0.35s, box-shadow 0.35s;
  min-height: 230px;
}
.kind:hover {
  transform: translateY(-8px);
  box-shadow: 0 18px 40px rgba(22, 50, 92, 0.1);
}
.kind-eq {
  font-family: var(--serif);
  font-size: 2rem;
  color: var(--cyan);
}

/* Puzzle */
.puzzle-section {
  background: var(--paper);
}
.puzzle-status {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  color: var(--blue);
  margin: -20px 0 24px;
}
.puzzle-board {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 28px;
}
.graphs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.graph-card, .say-card {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 16px;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
}
.graph-card {
  padding: 12px 12px 16px;
  color: var(--navy);
  background:
    linear-gradient(#fff, #fff) padding-box,
    linear-gradient(180deg, #fff, #f4f9fc) border-box;
  background-image:
    linear-gradient(rgba(22, 50, 92, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(22, 50, 92, 0.05) 1px, transparent 1px);
  background-size: 16px 16px;
  background-color: #fff;
}
.graph-card span {
  display: block;
  margin-top: 4px;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.graph-svg { width: 100%; height: auto; }
.say-card {
  display: block;
  width: 100%;
  padding: 20px 18px;
  margin-bottom: 12px;
  font-family: var(--serif);
  font-size: 1.2rem;
  font-style: italic;
  color: var(--navy);
}
.graph-card:hover, .say-card:hover {
  transform: translateY(-3px);
  border-color: var(--sky);
}
.graph-card.selected, .say-card.selected {
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(196, 163, 90, 0.25);
}
.graph-card.matched, .say-card.matched {
  border-color: var(--cyan);
  background: linear-gradient(180deg, #f4fbfe, #fff);
  pointer-events: none;
}
.graph-card.shake, .say-card.shake { animation: shake 0.4s; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}
.puzzle-done {
  margin-top: 28px;
  padding: 20px 24px;
  border-left: 2px solid var(--gold);
  font-family: var(--serif);
  font-size: 1.25rem;
  color: var(--navy);
}

/* Author */
.author-section {
  background: linear-gradient(180deg, #f3f7fb, #eef3f8);
}
.author-grid {
  display: grid;
  grid-template-columns: 0.78fr 1.22fr;
  gap: 48px;
  align-items: center;
  margin-bottom: 36px;
}
.mono-ring {
  aspect-ratio: 1;
  border-radius: 50%;
  border: 1px solid var(--gold);
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 30% 30%, rgba(78, 196, 232, 0.2), transparent 45%),
    #fff;
  position: relative;
  overflow: hidden;
}
.mono-ring::before {
  content: "";
  position: absolute;
  inset: 18px;
  border: 1px dashed rgba(22, 50, 92, 0.18);
  border-radius: 50%;
  animation: spin 28s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.mono-init {
  font-family: var(--serif);
  font-size: clamp(3rem, 6vw, 5rem);
  color: var(--navy);
  line-height: 1;
}
.mono-eq {
  position: absolute;
  bottom: 18%;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  color: var(--blue);
}
.stats {
  list-style: none;
  padding: 0;
  margin: 22px 0 0;
  display: grid;
  gap: 8px;
}
.stats li { color: var(--muted); font-size: 0.95rem; }
.stats strong {
  font-family: var(--serif);
  font-size: 1.4rem;
  color: var(--navy);
  margin-right: 6px;
}
.author-prose p { font-size: 1.05rem; color: #334155; }
.cred-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

/* Quote */
.quote-band {
  padding: 100px 0;
  text-align: center;
  background:
    radial-gradient(800px 300px at 50% 50%, rgba(78, 196, 232, 0.16), transparent 70%),
    var(--navy-deep);
  color: var(--cream);
}
.quote-label {
  font-family: var(--mono);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  font-size: 0.72rem;
  color: var(--gold-soft);
  margin: 0 0 16px;
}
.quote-band blockquote {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-style: italic;
  color: #fff;
}
.quote-author { color: var(--sky); margin: 16px 0 0; }

/* Footer */
.site-footer {
  background: var(--navy-deep);
  color: #c9d6e5;
  padding: 48px 0 36px;
  border-top: 1px solid rgba(196, 163, 90, 0.25);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr auto;
  gap: 24px;
  align-items: end;
}
.footer-title {
  font-family: var(--serif);
  font-size: 1.7rem;
  color: #fff;
  margin: 0;
}
.footer-title em { color: var(--gold-soft); }
.footer-sub { margin: 6px 0 0; font-size: 0.9rem; }
.site-footer nav { display: flex; gap: 18px; flex-wrap: wrap; }
.site-footer a { color: #c9d6e5; text-decoration: none; font-size: 0.9rem; }
.site-footer a:hover { color: var(--gold-soft); }
.copyright { margin: 0; font-size: 0.82rem; color: #8ea0b5; }

/* Reveal */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.reveal.in { opacity: 1; transform: none; }
.delay-1 { transition-delay: 0.12s; }
.delay-2 { transition-delay: 0.24s; }
.delay-3 { transition-delay: 0.36s; }

@media (max-width: 980px) {
  .hero-inner, .book-layout, .author-grid, .puzzle-board, .footer-grid {
    grid-template-columns: 1fr;
  }
  .anatomy, .kind-grid, .cred-row { grid-template-columns: 1fr 1fr; }
  .cover-card { position: static; max-width: 380px; }
  .book-img { width: min(100%, 340px); }
  .menu-btn { display: flex; }
  .nav {
    position: fixed;
    inset: var(--header) 16px auto;
    background: rgba(251, 252, 254, 0.96);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 18px;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
    display: none;
    box-shadow: 0 20px 40px rgba(12, 31, 56, 0.12);
  }
  .nav.open { display: flex; z-index: 60; }
}

@media (max-width: 640px) {
  .anatomy, .kind-grid, .cred-row { grid-template-columns: 1fr; }
  .graphs { grid-template-columns: 1fr; }
  .hero { padding-bottom: 90px; min-height: auto; }
  .section { padding: 80px 0; }
  .book-img { width: min(88%, 300px); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}