:root {
  --design-token-interaction: "Interaction:** Interaction*";
  --aged-vellum: #f5ece0;
  --darkroom-umber: #1e1a14;
  --roasted-ink: #2c2418;
  --parchment-glow: #f0e6d4;
  --brass-signal: #c4943e;
  --oxidized-copper: #6b8f7a;
  --driftwood: #a0896a;
  --amber-wash: #e8c87440;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--aged-vellum);
  color: var(--roasted-ink);
  font-family: "Source Serif 4", Georgia, serif;
  font-weight: 400;
  font-size: clamp(1rem, 1.1vw, 1.15rem);
  line-height: 1.72;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 50;
  opacity: 0.12;
  background-image: linear-gradient(90deg, rgba(30, 26, 20, 0.18) 1px, transparent 1px), linear-gradient(rgba(30, 26, 20, 0.08) 1px, transparent 1px);
  background-size: 8px 8px, 100% 6px;
  mix-blend-mode: multiply;
}

main {
  position: relative;
}

h1,
h2,
.classification,
.chapter-divider,
.margin-notes,
figcaption,
.section-number {
  font-family: "Space Mono", monospace;
}

.hero {
  min-height: 100vh;
  position: relative;
  overflow: hidden;
  background: var(--darkroom-umber);
  color: var(--parchment-glow);
}

.hero-photo {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--brass-signal), var(--darkroom-umber));
}

.hero-photo::before,
.hero-photo::after,
.duotone-image::before,
.duotone-image::after {
  content: "";
  position: absolute;
  inset: -12%;
}

.hero-photo::before {
  background: radial-gradient(circle at 25% 18%, rgba(196, 148, 62, 0.55), transparent 28%), radial-gradient(circle at 74% 38%, rgba(107, 143, 122, 0.24), transparent 23%), linear-gradient(115deg, transparent 0 35%, rgba(245, 236, 224, 0.12) 36% 37%, transparent 38% 100%);
  filter: grayscale(100%) sepia(40%) brightness(0.9) contrast(1.2);
  mix-blend-mode: multiply;
}

.hero-photo::after {
  background: repeating-linear-gradient(90deg, rgba(240, 230, 212, 0.04) 0 1px, transparent 1px 38px), repeating-linear-gradient(0deg, rgba(160, 137, 106, 0.04) 0 1px, transparent 1px 40px);
}

.duotone-image {
  position: absolute;
  inset: 0;
  filter: grayscale(100%) sepia(40%) brightness(0.9) contrast(1.2);
  mix-blend-mode: multiply;
}

.duotone-image::before {
  background: linear-gradient(72deg, rgba(30, 26, 20, 0.85) 0 26%, transparent 27% 48%, rgba(196, 148, 62, 0.18) 49% 52%, transparent 53%), radial-gradient(ellipse at 60% 70%, rgba(245, 236, 224, 0.24), transparent 34%);
}

.duotone-image::after {
  opacity: 0.48;
  background: repeating-linear-gradient(118deg, transparent 0 28px, rgba(196, 148, 62, 0.18) 29px, transparent 31px), radial-gradient(circle at 10% 80%, rgba(30, 26, 20, 0.9), transparent 32%);
}

.classification {
  position: absolute;
  top: 38px;
  right: 42px;
  z-index: 3;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgba(240, 230, 212, 0.76);
}

.hero-title-block {
  position: absolute;
  left: 8%;
  top: 58%;
  transform: translateY(-50%);
  z-index: 2;
  transition: opacity 800ms ease, transform 800ms ease;
}

.hero-title-block.scrolled-past {
  opacity: 0;
  transform: translateY(calc(-50% - 30px));
}

h1 {
  margin: 0;
  font-weight: 700;
  font-size: clamp(4rem, 12vw, 10rem);
  line-height: 0.9;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-title-block p {
  max-width: 720px;
  margin: 22px 0 0 8px;
  font-size: clamp(1.25rem, 2.4vw, 2rem);
  font-style: italic;
  color: rgba(240, 230, 212, 0.88);
}

.hero-rule {
  position: absolute;
  left: 0;
  top: 85%;
  width: 100%;
  height: 1px;
  background: rgba(160, 137, 106, 0.48);
}

.reg-circle {
  position: absolute;
  border: 1px solid rgba(160, 137, 106, 0.25);
  border-radius: 50%;
  animation: rotate 60s linear infinite;
  pointer-events: none;
}

.reg-circle::before,
.reg-circle::after {
  content: "";
  position: absolute;
  background: rgba(160, 137, 106, 0.4);
}

.reg-circle::before {
  width: 140%;
  height: 1px;
  left: -20%;
  top: 50%;
}

.reg-circle::after {
  width: 1px;
  height: 140%;
  left: 50%;
  top: -20%;
}

.hero-reg-circle {
  width: 200px;
  height: 200px;
  left: 24%;
  top: -34px;
}

.chapter {
  position: relative;
  padding-bottom: 130px;
  background: var(--aged-vellum);
}

.chapter::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 220px;
  opacity: 0.05;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, var(--driftwood) 0 1px, transparent 1px 40px), repeating-linear-gradient(0deg, var(--driftwood) 0 1px, transparent 1px 40px);
}

.dark-chapter {
  background: var(--darkroom-umber);
  color: var(--parchment-glow);
}

.chapter-divider {
  height: 120px;
  display: grid;
  grid-template-columns: minmax(80px, 1fr) minmax(160px, 8fr) minmax(160px, 2fr);
  gap: 22px;
  align-items: center;
  width: min(1180px, 84vw);
  margin: 0 auto;
  color: rgba(160, 137, 106, 0.7);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.chapter-divider i {
  display: block;
  height: 1px;
  background: rgba(160, 137, 106, 0.4);
}

.editorial-grid {
  width: min(1180px, 84vw);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 24px;
  position: relative;
}

.primary-flow {
  grid-column: 2 / span 7;
}

.primary-flow.narrow {
  grid-column: 2 / span 6;
}

.primary-flow.wide-reading {
  grid-column: 2 / span 8;
}

.margin-notes {
  grid-column: 9 / span 3;
  padding-top: 72px;
  color: rgba(160, 137, 106, 0.7);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  line-height: 1.58;
  text-transform: uppercase;
}

.margin-notes p {
  position: relative;
  margin: 0 0 32px;
  padding-left: 18px;
  border-left: 1px solid rgba(196, 148, 62, 0.45);
}

.section-head {
  position: relative;
  margin: 78px 0 40px;
}

.section-head h2 {
  margin: 0;
  color: var(--roasted-ink);
  font-weight: 700;
  font-size: clamp(1.8rem, 4.5vw, 3.6rem);
  letter-spacing: 0.04em;
  line-height: 1.05;
  text-transform: uppercase;
}

.dark-chapter .section-head h2 {
  color: var(--parchment-glow);
}

.section-number {
  display: block;
  color: var(--brass-signal);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}

.reg-circle.small {
  width: 120px;
  height: 120px;
  left: -52px;
  top: -34px;
  opacity: 0.9;
}

p {
  margin: 0 0 1.5em;
}

.pull-quote {
  margin: 54px 0 54px 60px;
  padding-left: 26px;
  border-left: 3px solid var(--brass-signal);
  color: var(--roasted-ink);
  font-weight: 600;
  font-style: italic;
  font-size: clamp(1.3rem, 2.2vw, 1.8rem);
  line-height: 1.45;
}

.dark-chapter .pull-quote {
  color: var(--parchment-glow);
}

.full-bleed {
  grid-column: 1 / -1;
  margin: 82px 0 30px;
  position: relative;
}

.full-bleed::before {
  content: "";
  position: absolute;
  width: 0;
  height: 0;
  right: 0;
  top: 0;
  border-top: 24px solid rgba(196, 148, 62, 0.15);
  border-left: 24px solid transparent;
  z-index: 3;
}

figcaption {
  margin-top: 16px;
  color: rgba(160, 137, 106, 0.78);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  line-height: 1.55;
  text-transform: uppercase;
}

.diagram-panel,
.grid-figure,
.trace-board {
  padding: 0;
}

.instrument-image {
  min-height: clamp(360px, 52vw, 640px);
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--brass-signal), var(--darkroom-umber));
  box-shadow: inset 0 0 0 1px rgba(160, 137, 106, 0.42);
}

.instrument-image::before,
.instrument-image::after {
  content: "";
  position: absolute;
  inset: 0;
  filter: grayscale(100%) sepia(40%) brightness(0.9) contrast(1.2);
  mix-blend-mode: multiply;
}

.image-one::before {
  background: radial-gradient(circle at 18% 55%, rgba(240, 230, 212, 0.24), transparent 18%), radial-gradient(circle at 76% 42%, rgba(196, 148, 62, 0.65), transparent 24%), repeating-linear-gradient(90deg, rgba(30, 26, 20, 0.88) 0 8px, transparent 8px 34px), linear-gradient(125deg, transparent 0 45%, rgba(245, 236, 224, 0.24) 45% 47%, transparent 47% 100%);
}

.image-one::after {
  background: repeating-linear-gradient(0deg, transparent 0 40px, rgba(160, 137, 106, 0.25) 41px, transparent 42px), radial-gradient(ellipse at 50% 100%, rgba(30, 26, 20, 0.9), transparent 46%);
}

.image-two::before {
  background: radial-gradient(circle at 50% 50%, rgba(196, 148, 62, 0.6), transparent 16%), radial-gradient(circle at 50% 50%, transparent 0 19%, rgba(30, 26, 20, 0.82) 20% 23%, transparent 24%), linear-gradient(90deg, rgba(30, 26, 20, 0.88) 0 18%, transparent 18% 82%, rgba(30, 26, 20, 0.9) 82% 100%);
}

.image-two::after {
  background: repeating-linear-gradient(90deg, transparent 0 58px, rgba(240, 230, 212, 0.14) 59px, transparent 60px), linear-gradient(28deg, transparent 0 55%, rgba(196, 148, 62, 0.24) 56% 57%, transparent 58%);
}

.grid-figure {
  background: var(--parchment-glow);
  padding: 56px;
  box-shadow: inset 0 0 0 1px rgba(160, 137, 106, 0.35);
}

.paper-map {
  min-height: 460px;
  position: relative;
  background-color: rgba(245, 236, 224, 0.8);
  background-image: repeating-linear-gradient(90deg, rgba(160, 137, 106, 0.18) 0 1px, transparent 1px 40px), repeating-linear-gradient(0deg, rgba(160, 137, 106, 0.18) 0 1px, transparent 1px 40px);
  overflow: hidden;
}

.paper-map::before {
  content: "";
  position: absolute;
  width: 180px;
  height: 180px;
  left: 18%;
  top: 18%;
  border: 1px solid rgba(160, 137, 106, 0.5);
  border-radius: 50%;
}

.paper-map::after {
  content: "";
  position: absolute;
  width: 420px;
  height: 1px;
  right: 10%;
  bottom: 30%;
  background: rgba(160, 137, 106, 0.35);
  transform: rotate(-24deg);
}

.paper-map span {
  position: absolute;
  width: 20px;
  height: 20px;
  background: rgba(196, 148, 62, 0.15);
  clip-path: polygon(0 0, 100% 0, 0 100%);
}

.paper-map span:nth-child(1) { left: 8%; top: 10%; }
.paper-map span:nth-child(2) { right: 10%; top: 15%; transform: rotate(90deg); }
.paper-map span:nth-child(3) { left: 15%; bottom: 12%; transform: rotate(-90deg); }
.paper-map span:nth-child(4) { right: 16%; bottom: 18%; transform: rotate(180deg); }

.trace-board {
  min-height: 520px;
  background: var(--darkroom-umber);
  overflow: hidden;
  box-shadow: inset 0 0 0 1px rgba(160, 137, 106, 0.38);
  background-image: repeating-linear-gradient(90deg, rgba(160, 137, 106, 0.08) 0 1px, transparent 1px 40px), repeating-linear-gradient(0deg, rgba(160, 137, 106, 0.08) 0 1px, transparent 1px 40px);
}

.trace-line {
  position: absolute;
  left: -6%;
  right: -6%;
  top: 42%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--brass-signal), transparent);
  transform: rotate(-7deg);
  box-shadow: 0 0 28px rgba(196, 148, 62, 0.5);
}

.trace-line.delayed {
  top: 56%;
  transform: rotate(4deg);
  background: linear-gradient(90deg, transparent, var(--oxidized-copper), transparent);
}

.trace-node {
  position: absolute;
  width: 90px;
  height: 90px;
  border: 1px solid rgba(196, 148, 62, 0.55);
  border-radius: 50%;
}

.trace-node.one { left: 16%; top: 32%; }
.trace-node.two { left: 48%; top: 47%; }
.trace-node.three { right: 16%; top: 26%; }

.trace-board figcaption {
  position: absolute;
  left: 24px;
  bottom: 16px;
}

.final-chapter {
  padding-bottom: 220px;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms cubic-bezier(0.23, 1, 0.32, 1), transform 600ms cubic-bezier(0.23, 1, 0.32, 1);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.margin-notes.reveal {
  transition-delay: 200ms;
}

.tracking-reticle {
  width: 40px;
  height: 40px;
  border: 1px solid var(--brass-signal);
  border-radius: 50%;
  position: fixed;
  left: 0;
  top: 0;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.5;
  will-change: transform;
  transition: width 0.4s cubic-bezier(0.23, 1, 0.32, 1), height 0.4s cubic-bezier(0.23, 1, 0.32, 1), opacity 0.3s ease, border-color 0.3s ease;
}

.tracking-reticle.is-focused {
  width: 80px;
  height: 80px;
  opacity: 0.8;
}

.tracking-reticle.is-dormant {
  width: 20px;
  height: 20px;
  opacity: 0.2;
}

@keyframes rotate {
  to { transform: rotate(360deg); }
}

@media (max-width: 1024px) {
  .editorial-grid {
    grid-template-columns: repeat(8, minmax(0, 1fr));
  }

  .primary-flow,
  .primary-flow.narrow,
  .primary-flow.wide-reading {
    grid-column: 1 / span 6;
  }

  .margin-notes {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
    padding-top: 10px;
  }

  .full-bleed {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  .classification {
    left: 22px;
    right: auto;
    top: 24px;
  }

  .hero-title-block {
    left: 22px;
    right: 18px;
  }

  h1 {
    font-size: clamp(3.3rem, 18vw, 5rem);
  }

  .chapter-divider,
  .editorial-grid {
    width: calc(100vw - 36px);
  }

  .chapter-divider {
    grid-template-columns: 50px 1fr;
  }

  .chapter-divider span:last-child {
    grid-column: 1 / -1;
  }

  .editorial-grid {
    display: block;
  }

  .margin-notes {
    display: block;
    margin: 28px 0 0;
    padding: 18px;
    border: 1px solid rgba(160, 137, 106, 0.35);
    background: rgba(232, 200, 116, 0.12);
  }

  .pull-quote {
    margin-left: 18px;
  }

  .grid-figure {
    padding: 24px;
  }
}