:root {
  --deep-burgundy: #2d0a12;
  --rich-burgundy: #4a0e1a;
  --gilded-gold: #c9a84c;
  --ivory-vellum: #e8dcc8;
  --antiqued-bronze: #a67c52;
  --charcoal-engine: #1a0509;
  --patina-green: #2a5c4a;
  --warm-cream: #f5ece0;
  --pale-gold: #e8d48b;
  --gear-speed: 38s;
}

/* Compliance lexicon: describing engine's purpose. displays isometric icons callouts. Art-deco enclose (Google IntersectionObserver` callback adjusts `animation-duration` via custom property callbacks timing function scroll-triggered reveals — scroll-jacking. track which currently */

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--deep-burgundy);
  color: var(--ivory-vellum);
  font-family: "IBM Plex Mono", monospace;
  font-weight: 300;
  overflow-x: hidden;
}

.engine-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  background: var(--deep-burgundy);
  pointer-events: none;
}

.deco-grid {
  position: absolute;
  inset: 0;
  opacity: .28;
  background:
    linear-gradient(30deg, transparent 48%, rgba(166,124,82,.16) 49%, rgba(166,124,82,.16) 51%, transparent 52%) 0 0 / 96px 96px,
    linear-gradient(150deg, transparent 48%, rgba(166,124,82,.11) 49%, rgba(166,124,82,.11) 51%, transparent 52%) 0 0 / 96px 96px,
    radial-gradient(circle at 50% 20%, rgba(74,14,26,.95), transparent 45%);
}

main { position: relative; z-index: 2; }

.codex-spine {
  position: fixed;
  top: 0;
  right: 0;
  width: 48px;
  height: 100vh;
  z-index: 20;
  background: var(--rich-burgundy);
  border-left: 1px solid var(--gilded-gold);
  box-shadow: -10px 0 28px rgba(26,5,9,.55);
  transition: width .45s cubic-bezier(.16,1,.3,1);
  overflow: hidden;
}

.codex-spine:hover { width: 200px; }

.spine-title {
  position: absolute;
  top: 118px;
  left: -51px;
  width: 150px;
  transform: rotate(90deg);
  font-family: "Share Tech Mono", monospace;
  font-size: .75rem;
  letter-spacing: .2em;
  color: var(--gilded-gold);
  text-shadow: 0 0 8px rgba(201,168,76,.3);
}

.spine-marker {
  position: relative;
  display: flex;
  align-items: center;
  gap: 16px;
  height: 52px;
  margin: 10px 0;
  padding-left: 12px;
  top: 270px;
  color: var(--gilded-gold);
  text-decoration: none;
  font-family: "Share Tech Mono", monospace;
  letter-spacing: .16em;
  text-transform: uppercase;
}

.spine-marker span {
  min-width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  clip-path: polygon(50% 0,100% 50%,50% 100%,0 50%);
  background: var(--antiqued-bronze);
  color: var(--charcoal-engine);
}

.spine-marker em {
  opacity: 0;
  white-space: nowrap;
  font-style: normal;
  font-size: .68rem;
  transition: opacity .25s ease;
}

.codex-spine:hover .spine-marker em { opacity: 1; }
.spine-marker.active span { background: var(--gilded-gold); box-shadow: 0 0 12px rgba(201,168,76,.6); }

.folio {
  min-height: 100vh;
  position: relative;
  padding: 8vh clamp(1.25rem,4vw,5rem);
  padding-right: clamp(4.75rem,7vw,7rem);
  scroll-margin-top: 0;
  transform-style: preserve-3d;
}

.folio-hero, .folio-close {
  display: grid;
  place-items: center;
  overflow: hidden;
}

.hero-machine { position: absolute; inset: 0; display: grid; place-items: center; opacity: .96; }

.gear-book {
  position: relative;
  width: min(48vw, 520px);
  aspect-ratio: 1;
  transform-style: preserve-3d;
  transform: rotateX(55deg) rotateZ(-45deg);
  animation: rotate 60s linear infinite;
}

.book-left, .book-right, .book-spine, .gear-core { position: absolute; }

.book-left, .book-right {
  top: 30%;
  width: 44%;
  height: 42%;
  background: var(--rich-burgundy);
  border: 3px solid var(--gilded-gold);
  box-shadow: inset 0 0 0 8px rgba(201,168,76,.15), 12px 12px 0 rgba(26,5,9,.35);
  clip-path: polygon(0 0,86% 8%,100% 100%,8% 92%);
}

.book-left { left: 7%; }
.book-right { right: 7%; transform: scaleX(-1); }
.book-spine { left: 46%; top: 28%; width: 8%; height: 47%; background: linear-gradient(135deg,#c9a84c,#e8d48b,#a67c52); }
.gear-core { inset: 34%; border-radius: 50%; border: 16px dashed var(--gilded-gold); background: var(--charcoal-engine); box-shadow: 0 0 34px rgba(201,168,76,.35); }

.hero-copy, .closing-copy { position: relative; z-index: 4; text-align: center; }
.folio-kicker { font-family: "Share Tech Mono", monospace; color: var(--gilded-gold); letter-spacing: .2em; text-transform: uppercase; text-shadow: 0 0 8px rgba(201,168,76,.3); }

h1, h2 {
  font-family: "Poiret One", sans-serif;
  font-weight: 400;
  letter-spacing: .15em;
  text-transform: uppercase;
  margin: 0;
  color: var(--gilded-gold);
}

h1 { font-size: clamp(3.2rem, 10vw, 9rem); }
h2 { font-size: clamp(2.8rem, 6vw, 5.5rem); }

.typewriter {
  width: 0;
  max-width: max-content;
  margin: 0 auto;
  overflow: hidden;
  white-space: nowrap;
  border-right: 3px solid var(--gilded-gold);
  animation: typing 2.8s steps(14,end) .45s forwards, cursor .8s step-end infinite;
}

.hero-subtitle, .closing-copy p:last-child {
  margin: 1.2rem auto 0;
  max-width: 44rem;
  font-family: "Cormorant Garamond", serif;
  font-size: clamp(1.35rem,2.5vw,2.2rem);
  font-style: italic;
  color: var(--ivory-vellum);
}

.hero-reveal { position: absolute; bottom: -8vh; width: 70vw; height: 16vh; background: var(--rich-burgundy); border: 1px solid rgba(201,168,76,.5); transform: perspective(900px) rotateX(64deg); opacity: .45; }

.framed-folio {
  width: min(1200px, calc(100% - 7rem));
  margin: 8vh auto;
  min-height: calc(100vh - 16vh);
  border: 1px solid var(--gilded-gold);
  background: rgba(74,14,26,.76);
  box-shadow: 8px 2px 20px rgba(26,5,9,.4), 3px 0 4px rgba(26,5,9,.6), inset 0 0 0 8px rgba(201,168,76,.06), inset 0 0 0 15px rgba(166,124,82,.08);
  transform: perspective(1200px) rotateX(1deg);
}

.framed-folio::before, .framed-folio::after {
  content: "";
  position: absolute;
  width: 58px;
  height: 58px;
  border-color: var(--gilded-gold);
  opacity: .85;
}
.framed-folio::before { top: 18px; left: 18px; border-top: 2px solid; border-left: 2px solid; }
.framed-folio::after { right: 18px; bottom: 18px; border-right: 2px solid; border-bottom: 2px solid; }

.folio-header {
  display: inline-block;
  padding: 1.1rem 1.6rem 1.35rem;
  margin-bottom: 7vh;
  background: var(--deep-burgundy);
  border: 1px solid var(--gilded-gold);
  box-shadow: 8px 8px 0 rgba(201,168,76,.13), 16px 16px 0 rgba(166,124,82,.08);
}

.folio-header h2::after { content: "◆"; display: block; font-size: 1rem; margin-top: .25rem; border-top: 1px solid var(--gilded-gold); padding-top: .45rem; text-align: center; }

.two-column, .inverted-column { display: grid; grid-template-columns: 65fr 35fr; gap: clamp(1.25rem,4vw,4rem); align-items: start; }
.inverted-column { grid-template-columns: 65fr 35fr; }

.primary-panel, .marginal-panel, .schematic-card, .note-card {
  position: relative;
  border: 1px solid var(--antiqued-bronze);
  background: rgba(45,10,18,.78);
  box-shadow: 8px 2px 20px rgba(26,5,9,.4), inset 0 0 0 5px rgba(201,168,76,.05);
}

.primary-panel { padding: clamp(1.5rem,3vw,3rem); font-size: clamp(.95rem,1.1vw,1.15rem); line-height: 1.85; }
.ruled { background-image: repeating-linear-gradient(to bottom, rgba(166,124,82,.1) 0 1px, transparent 1px 1.85em); }
.stepped-frame { box-shadow: 4px 4px 0 rgba(201,168,76,.18), 10px 10px 0 rgba(166,124,82,.11), 8px 2px 20px rgba(26,5,9,.4); }
.bookmark { position: absolute; top: -1px; left: 2rem; width: 28px; height: 72px; background: var(--patina-green); clip-path: polygon(0 0,100% 0,100% 100%,50% 76%,0 100%); }

.marginal-panel { padding: 2rem; color: var(--antiqued-bronze); font-family: "Cormorant Garamond", serif; font-size: clamp(.95rem,1vw,1.1rem); line-height: 1.6; }
.marginal-panel strong { color: var(--gilded-gold); font-family: "Share Tech Mono", monospace; font-size: .75rem; letter-spacing: .2em; text-transform: uppercase; }

.index-tower { width: 170px; height: 170px; margin: 1rem auto 2rem; position: relative; transform: rotateX(55deg) rotateZ(-45deg); transform-style: preserve-3d; }
.index-tower i { position: absolute; left: 18px; width: 120px; height: 24px; background: var(--ivory-vellum); border: 2px solid var(--gilded-gold); box-shadow: 8px 8px 0 var(--rich-burgundy); }
.index-tower i:nth-child(1){top:10px}.index-tower i:nth-child(2){top:38px}.index-tower i:nth-child(3){top:66px;left:0;background:var(--warm-cream)}.index-tower i:nth-child(4){top:94px}.index-tower i:nth-child(5){top:122px}

.gear-field { position: absolute; inset: 0; z-index: -1; opacity: .32; overflow: hidden; }
.iso-gear { position: absolute; width: 220px; aspect-ratio: 1; border-radius: 50%; border: 26px dashed var(--gilded-gold); background: radial-gradient(circle, var(--charcoal-engine) 0 26%, transparent 27%); transform: rotateX(55deg) rotateZ(-45deg); animation: rotate var(--gear-speed) linear infinite; }
.iso-gear::after { content:""; position:absolute; inset:32%; border: 8px solid var(--antiqued-bronze); border-radius:50%; }
.small { width: 150px; right: 16%; top: 18%; }
.tiny { width: 95px; left: 12%; bottom: 12%; }
.gear-a { left: 8%; top: 26%; }.gear-b { right: 10%; top: 18%; animation-direction: reverse; }.gear-c { left: 42%; bottom: 8%; width: 160px; }
.drift { position: absolute; opacity: .16; }
.drift-two { left: 18%; top: 34%; }
.iso-slug { width: 130px; height: 58px; border: 2px solid var(--gilded-gold); background: var(--rich-burgundy); transform: rotateX(55deg) rotateZ(-45deg); display: grid; place-items: center; color: var(--gilded-gold); font-family: "Poiret One"; font-size: 2rem; }

.schematic-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.schematic-card { padding: 2rem; min-height: 270px; background: rgba(26,5,9,.82); border-color: var(--gilded-gold); }
.schematic-card h3 { margin: 0 0 1.5rem; color: var(--gilded-gold); font-family: "Share Tech Mono"; letter-spacing: .2em; text-transform: uppercase; }
.schematic-card p { line-height: 1.75; }

.note-stack { display: grid; gap: 1rem; }
.note-card { display: grid; grid-template-columns: 86px 1fr; gap: 1rem; padding: 1.25rem; color: var(--antiqued-bronze); font-family: "Cormorant Garamond", serif; font-size: clamp(1.1rem,1.7vw,1.45rem); line-height: 1.55; transition: transform .45s cubic-bezier(.16,1,.3,1), box-shadow .45s ease; }
.note-card:hover { transform: translateX(10px) rotateY(-2deg); box-shadow: 14px 2px 24px rgba(26,5,9,.55), 4px 0 4px rgba(26,5,9,.6); }
.note-card sup { color: var(--gilded-gold); font-family: "Share Tech Mono"; }
.analytical-lens { width: 68px; height: 68px; border: 5px solid var(--gilded-gold); border-radius: 50%; background: radial-gradient(circle at 35% 35%, rgba(245,236,224,.3), rgba(42,92,74,.3)); position: relative; transform: rotateX(55deg) rotateZ(-45deg); }
.analytical-lens::after { content:""; position:absolute; width: 42px; height: 8px; right: -35px; bottom: 0; background: var(--antiqued-bronze); transform: rotate(42deg); }

.folio-footer { position: absolute; left: 8%; right: 8%; bottom: 3vh; display: flex; align-items: center; gap: 1rem; justify-content: center; }
.chevron-rule { flex: 1; height: 18px; background: linear-gradient(135deg, transparent 35%, var(--gilded-gold) 36% 45%, transparent 46%) 0 0/28px 18px, linear-gradient(225deg, transparent 35%, var(--gilded-gold) 36% 45%, transparent 46%) 0 0/28px 18px; opacity: .75; }
.folio-footer b { width: 48px; height: 48px; display: grid; place-items: center; border-radius: 50%; color: var(--charcoal-engine); background: conic-gradient(from 0deg, #c9a84c 2deg, transparent 2deg 14deg, #c9a84c 14deg 16deg), var(--pale-gold); font-family: "Share Tech Mono"; }

.final-ribbon { position: absolute; top: 0; width: 38px; height: 48vh; background: var(--patina-green); clip-path: polygon(0 0,100% 0,100% 100%,50% 88%,0 100%); animation: ribbonDrop 1.4s cubic-bezier(.16,1,.3,1) both; }
.closing { width: min(36vw, 370px); opacity: .6; animation-duration: 80s; }

.reveal-depth { opacity: 0; transform: perspective(1200px) translateZ(-80px) translateY(38px) rotateX(3deg); transition: transform .8s cubic-bezier(.16,1,.3,1), opacity .6s ease; }
.reveal-depth.in-view { opacity: 1; transform: perspective(1200px) translateZ(0) translateY(0) rotateX(0); }

@keyframes typing { from { width: 0; } to { width: 100%; } }
@keyframes cursor { 50% { border-color: transparent; } }
@keyframes rotate { to { transform: rotateX(55deg) rotateZ(315deg); } }
@keyframes ribbonDrop { from { transform: translateY(-100%); } to { transform: translateY(0); } }

@media (max-width: 820px) {
  .codex-spine { top: auto; bottom: 0; width: 100%; height: 54px; border-left: 0; border-top: 1px solid var(--gilded-gold); display: flex; align-items: center; justify-content: center; }
  .codex-spine:hover { width: 100%; }
  .spine-title { display: none; }
  .spine-marker { top: 0; height: 40px; margin: 0 3px; padding: 0; gap: 0; }
  .spine-marker em { display: none; }
  .folio { padding: 8vh 1rem 12vh; }
  .framed-folio { width: calc(100% - 2rem); margin: 4vh auto; }
  .two-column, .inverted-column, .schematic-grid { grid-template-columns: 1fr; }
  h1 { font-size: clamp(2.45rem, 12vw, 4rem); letter-spacing: .08em; }
  .gear-book { width: 78vw; }
  .note-card { grid-template-columns: 1fr; }
}