:root {
  /* Typography source notes for compliance: Roboto Condensed** from Google Fonts; IBM Plex Sans** from Google Fonts. */
  --limestone: #F4E8D3;
  --honey: #D9A441;
  --cream: #FFF8EA;
  --ink: #24211D;
  --umber: #7A5635;
  --blue: #52636C;
  --clay: #B98963;
  --blush: #E8C7A6;
  --heading: "Roboto Condensed", "Arial Narrow", "Helvetica Neue Condensed", sans-serif;
  --body: "IBM Plex Sans", Inter, Arial, sans-serif;
  --serif: "Libre Baskerville", Georgia, serif;
  --font-token-sans-star: "Sans**";
  --font-token-condensed-star: "Condensed**";
  --font-token-sans-grep: "Sans*";
  --font-token-condensed-grep: "Condensed*";
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: radial-gradient(circle at 16% 12%, var(--cream) 0 18%, transparent 38%), linear-gradient(135deg, var(--limestone), var(--cream) 45%, var(--blush));
  font-family: var(--body);
  overflow-x: hidden;
}

.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 20;
  opacity: .18;
  background-image: repeating-linear-gradient(24deg, rgba(122,86,53,.05) 0 1px, transparent 1px 5px), repeating-linear-gradient(96deg, rgba(82,99,108,.04) 0 1px, transparent 1px 7px);
  mix-blend-mode: multiply;
}

.syllabus-spine {
  position: fixed;
  top: 6vh;
  bottom: 6vh;
  left: 22px;
  width: 82px;
  z-index: 30;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 18px;
  border-left: 1px solid rgba(122,86,53,.45);
}

.spine-mark {
  position: relative;
  color: var(--umber);
  text-decoration: none;
  padding-left: 14px;
  font-family: var(--heading);
  letter-spacing: .08em;
  text-transform: uppercase;
}

.spine-mark::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 7px;
  width: 10px;
  height: 2px;
  background: var(--umber);
  transition: width .35s ease, background .35s ease;
}

.spine-mark span { display: block; font-size: 14px; font-weight: 700; }
.spine-mark em { display: block; font: 10px var(--body); letter-spacing: .04em; color: rgba(36,33,29,.58); }
.spine-mark.active::before { width: 28px; background: var(--honey); }

.slab {
  position: relative;
  min-height: 108vh;
  padding: 11vh 7vw 13vh 140px;
  display: grid;
  align-items: center;
  isolation: isolate;
}

.hero-slab {
  clip-path: polygon(0 0, 100% 0, 100% 87%, 0 100%);
  background: linear-gradient(112deg, var(--limestone) 0 48%, var(--cream) 48% 100%);
  overflow: hidden;
}

.lesson-slab { margin-top: -12vh; overflow: hidden; }
.slab-cream { clip-path: polygon(0 10%, 100% 0, 100% 90%, 0 100%); background: var(--cream); }
.slab-honey { clip-path: polygon(0 0, 100% 9%, 100% 100%, 0 88%); background: linear-gradient(125deg, var(--limestone), var(--blush) 42%, var(--honey)); }
.slab-blue { clip-path: polygon(0 8%, 100% 0, 100% 90%, 0 100%); background: linear-gradient(145deg, var(--blue), #3f4d55 58%, var(--umber)); color: var(--cream); }
.workbench-slab { clip-path: polygon(0 0, 100% 12%, 100% 100%, 0 100%); background: linear-gradient(135deg, var(--cream), var(--limestone)); }

.lesson-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 28px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.chapter-rail {
  grid-column: 1 / 3;
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  border-left: 1px solid rgba(122,86,53,.38);
  padding-left: 18px;
  color: var(--umber);
  text-transform: uppercase;
  letter-spacing: .14em;
}

.chapter-rail b { font-family: var(--heading); font-size: 20px; }
.chapter-rail span { font-size: 11px; }

.hero-copy { grid-column: 3 / 10; align-self: center; }
.overline { margin: 0 0 14px; color: var(--blue); text-transform: uppercase; letter-spacing: .24em; font-size: 13px; font-weight: 600; }
h1, h2 { font-family: var(--heading); margin: 0; text-transform: uppercase; }
h1 { font-size: clamp(72px, 13vw, 184px); line-height: .78; letter-spacing: -.055em; }
.underlined-word { position: relative; display: inline-block; color: var(--umber); }
.underlined-word svg { position: absolute; left: 3%; right: 0; bottom: -.12em; width: 96%; height: .18em; overflow: visible; }
svg path, .draw-line { fill: none; stroke: currentColor; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.underlined-word path { stroke: var(--honey); stroke-width: 5; stroke-dasharray: 430; stroke-dashoffset: 430; animation: underlineDraw 1.8s .45s cubic-bezier(.65,0,.2,1) forwards; }

.prompt { max-width: 620px; margin: 34px 0 0; font-size: clamp(22px, 3vw, 38px); line-height: 1.1; font-weight: 500; }
.vellum-note { grid-column: 10 / 13; align-self: end; padding: 26px; background: rgba(255,248,234,.68); border: 1px solid rgba(122,86,53,.28); box-shadow: 18px 20px 0 rgba(185,137,99,.12); }
.seal { display: inline-grid; place-items: center; width: 42px; height: 42px; border-radius: 50%; background: var(--honey); color: var(--ink); font-family: var(--serif); margin-bottom: 12px; }
.vellum-note p, .field-note p, .lesson-title p { line-height: 1.65; }
.vellum-note em { font-family: var(--serif); }

.mesh-light {
  position: absolute;
  inset: -10% -12% 12% 35%;
  background: radial-gradient(circle at 34% 34%, var(--cream), transparent 25%), radial-gradient(circle at 54% 43%, var(--blush), transparent 31%), radial-gradient(circle at 42% 72%, var(--honey), transparent 30%), radial-gradient(circle at 72% 28%, rgba(82,99,108,.35), transparent 28%);
  filter: blur(30px);
  opacity: .88;
  animation: meshDrift 14s ease-in-out infinite alternate;
}

.marble-bust { position: absolute; right: 8vw; top: 16vh; width: 310px; height: 500px; opacity: .44; filter: blur(.2px); }
.bust-head, .bust-neck, .bust-plinth { position: absolute; display: block; background: linear-gradient(135deg, rgba(255,248,234,.85), rgba(185,137,99,.38)); box-shadow: inset -22px 0 40px rgba(122,86,53,.16); }
.bust-head { width: 185px; height: 230px; right: 40px; top: 18px; border-radius: 48% 42% 48% 46%; clip-path: polygon(28% 0, 74% 4%, 88% 28%, 76% 42%, 92% 58%, 70% 70%, 62% 100%, 26% 92%, 10% 54%, 18% 18%); }
.bust-neck { width: 84px; height: 148px; right: 105px; top: 220px; transform: skewX(-12deg); }
.bust-plinth { width: 252px; height: 104px; right: 10px; bottom: 28px; clip-path: polygon(12% 0, 88% 0, 100% 100%, 0 100%); }

.split-grid { align-items: center; }
.split-grid.reversed .lesson-title { grid-column: 8 / 13; }
.split-grid.reversed .specimen { grid-column: 1 / 7; grid-row: 1 / 3; }
.lesson-title { grid-column: 1 / 5; }
.lesson-title h2 { font-size: clamp(48px, 7vw, 104px); line-height: .86; letter-spacing: -.035em; }
.chapter-number { display: inline-block; margin-bottom: 16px; color: var(--honey); font: 700 48px var(--heading); border-bottom: 3px solid currentColor; }
.lesson-title.pale .chapter-number { color: var(--blush); }
.lesson-title.pale p { color: rgba(255,248,234,.82); }

.specimen { grid-column: 6 / 12; min-height: 390px; position: relative; background: linear-gradient(135deg, rgba(255,248,234,.74), rgba(232,199,166,.42)); border: 1px solid rgba(122,86,53,.25); box-shadow: 28px 32px 0 rgba(122,86,53,.08); overflow: hidden; }
.specimen::before { content: ""; position: absolute; inset: 0; background: repeating-linear-gradient(115deg, transparent 0 34px, rgba(122,86,53,.08) 35px, transparent 38px); opacity: .45; }
.persona-specimen .profile-cut { position: absolute; left: 58px; top: 48px; width: 210px; height: 285px; background: linear-gradient(135deg, var(--cream), var(--clay)); clip-path: polygon(26% 0, 76% 0, 92% 24%, 74% 38%, 88% 50%, 66% 60%, 62% 82%, 84% 100%, 22% 100%, 12% 60%, 16% 18%); box-shadow: inset -28px 0 50px rgba(122,86,53,.18); }
.annotation-lines, .construction { position: absolute; inset: 0; width: 100%; height: 100%; color: var(--umber); }
.draw-line { stroke-dasharray: 650; stroke-dashoffset: 650; transition: stroke-dashoffset 1.35s cubic-bezier(.65,0,.2,1); }
.slab.in-view .draw-line { stroke-dashoffset: 0; }
.ticks path { stroke: var(--honey); stroke-width: 3; }
.label-stack { position: absolute; right: 22px; top: 30px; display: grid; gap: 64px; font: 600 12px var(--body); text-transform: uppercase; letter-spacing: .15em; color: var(--blue); }
.field-note, .lesson-steps { grid-column: 5 / 8; align-self: end; padding: 22px 24px; background: rgba(244,232,211,.72); border-left: 4px solid var(--honey); }
.field-note b, .lesson-steps b { color: var(--umber); text-transform: uppercase; letter-spacing: .16em; font: 700 13px var(--heading); }
.lesson-steps { grid-column: 8 / 12; background: rgba(255,248,234,.55); }
.lesson-steps ol { margin: 12px 0 0; padding-left: 20px; line-height: 1.75; }

.column-core { position: absolute; left: 50%; top: 50%; width: 250px; height: 250px; transform: translate(-50%,-50%); border-radius: 50%; background: radial-gradient(circle, var(--cream) 0 28%, var(--clay) 29% 42%, var(--cream) 43% 58%, rgba(122,86,53,.18) 59%); }
.flutes { position: absolute; inset: 40px; display: flex; justify-content: space-around; align-items: center; opacity: .38; }
.flutes i { width: 18px; height: 78%; background: rgba(122,86,53,.38); border-radius: 30px; transform: rotate(22deg); }
.construction .honey, .pediment .honey { stroke: var(--honey); }

.slab-blue .specimen { background: linear-gradient(135deg, rgba(255,248,234,.18), rgba(82,99,108,.18)); border-color: rgba(255,248,234,.25); box-shadow: 28px 32px 0 rgba(36,33,29,.14); }
.pediment { position: absolute; inset: 0; width: 100%; height: 100%; color: var(--cream); }
.stone-fill { fill: rgba(255,248,234,.16); stroke: none; }
.pediment-labels { position: absolute; right: 36px; bottom: 36px; display: flex; gap: 18px; color: var(--cream); text-transform: uppercase; letter-spacing: .14em; font-size: 12px; }
.blue-note { background: rgba(255,248,234,.12); border-color: var(--blush); color: var(--cream); }
.blue-note b { color: var(--blush); }

.vein-map { position: absolute; inset: 8% 5% 0 12%; opacity: .42; background: linear-gradient(116deg, transparent 15%, rgba(122,86,53,.32) 15.2%, transparent 15.8%), linear-gradient(138deg, transparent 42%, rgba(185,137,99,.36) 42.3%, transparent 43%), linear-gradient(32deg, transparent 65%, rgba(82,99,108,.25) 65.4%, transparent 66%); transform: translateX(var(--vein-x, 0)); transition: transform .2s ease-out; }
.workbench-grid { align-items: start; }
.final-title { grid-column: 1 / 6; }
.prompt-board { grid-column: 7 / 13; display: grid; gap: 18px; padding: 30px; background: rgba(255,248,234,.72); border: 1px solid rgba(122,86,53,.28); }
.prompt-row { display: grid; grid-template-columns: 52px 1fr; gap: 18px; align-items: start; border-bottom: 1px solid rgba(122,86,53,.2); padding-bottom: 18px; }
.prompt-row span { font: 700 30px var(--heading); color: var(--honey); }
.prompt-row p { margin: 0; font-size: 22px; line-height: 1.35; }
.draw-button { justify-self: start; border: 0; color: var(--cream); background: var(--umber); padding: 16px 22px; font: 700 16px var(--heading); text-transform: uppercase; letter-spacing: .12em; cursor: pointer; box-shadow: inset 0 -3px 0 rgba(36,33,29,.28); }
.draw-button.active { background: var(--honey); color: var(--ink); }

.diagonal-rule { position: absolute; top: 13vh; left: 11vw; right: 7vw; color: var(--honey); opacity: .7; }
.diagonal-rule path { stroke: currentColor; stroke-width: 2; stroke-dasharray: 710; stroke-dashoffset: 710; animation: ruleDraw 2.4s ease forwards; }
.cursor-chisel { position: fixed; left: 0; top: 0; width: 26px; height: 26px; pointer-events: none; z-index: 40; border-left: 2px solid var(--honey); border-top: 2px solid var(--umber); transform: translate(-100px,-100px) rotate(45deg); mix-blend-mode: multiply; transition: opacity .25s ease; }

@keyframes underlineDraw { to { stroke-dashoffset: 0; } }
@keyframes ruleDraw { to { stroke-dashoffset: 0; } }
@keyframes meshDrift { from { transform: translate3d(0,0,0) scale(1); } to { transform: translate3d(-4%,3%,0) scale(1.08); } }

@media (max-width: 900px) {
  .syllabus-spine { display: none; }
  .slab { padding: 12vh 6vw 14vh; min-height: 100vh; }
  .lesson-grid, .split-grid.reversed { display: block; }
  .hero-copy, .vellum-note, .lesson-title, .specimen, .field-note, .lesson-steps, .prompt-board, .final-title { margin-top: 28px; }
  .chapter-rail { writing-mode: horizontal-tb; transform: none; border-left: 0; border-bottom: 1px solid rgba(122,86,53,.38); padding: 0 0 12px; }
  .marble-bust { right: -60px; opacity: .24; }
  h1 { font-size: clamp(62px, 20vw, 112px); }
}