:root {
  /* Typography compliance trace: Space Grotes Grotesk* Grotesk** for explanatory body text and section fragments because it has modern clarity without becoming cold corporate UI. Use **IBM Plex Mono sparingly for atomic numbers. */
  --carbon-black: #050403;
  --graphite-sheen: #2B2D2F;
  --bone-paper: #E8DFC8;
  --ember-orange: #E4571E;
  --diamond-cyan: #8FE9FF;
  --soot-violet: #302239;
  --oxide-umber: #8A4B2A;
  --serif: "Instrument Serif", serif;
  --space: "Space Grotesk", sans-serif;
  --mono: "IBM Plex Mono", monospace;
  --mx: 50vw;
  --my: 50vh;
  --pressure: 0;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--carbon-black);
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--bone-paper);
  font-family: var(--space);
  background:
    radial-gradient(circle at 15% 20%, rgba(48, 34, 57, .62), transparent 34rem),
    radial-gradient(circle at 86% 70%, rgba(138, 75, 42, .28), transparent 30rem),
    var(--carbon-black);
  overflow-x: hidden;
}

#carbon-dust,
.grain,
.pressure-halo {
  position: fixed;
  inset: 0;
  pointer-events: none;
}

#carbon-dust { z-index: 3; mix-blend-mode: screen; opacity: .48; }

.grain {
  z-index: 4;
  opacity: .18;
  mix-blend-mode: overlay;
  background-image:
    repeating-radial-gradient(circle at 17% 23%, rgba(232, 223, 200, .22) 0 1px, transparent 1px 4px),
    repeating-linear-gradient(102deg, rgba(232, 223, 200, .08) 0 1px, transparent 1px 8px);
}

.pressure-halo {
  z-index: 2;
  opacity: calc(.18 + var(--pressure) * .42);
  background: radial-gradient(circle clamp(130px, calc(16vw + var(--pressure) * 220px), 460px) at var(--mx) var(--my), rgba(232, 223, 200, .19), rgba(143, 233, 255, .08) 24%, rgba(228, 87, 30, .05) 42%, transparent 66%);
  mix-blend-mode: screen;
  transition: opacity 500ms ease;
}

.allotrope-nav {
  position: fixed;
  right: 2rem;
  top: 50%;
  z-index: 8;
  transform: translateY(-50%);
  display: grid;
  gap: .72rem;
}

.allotrope-nav a {
  width: 2.4rem;
  height: 2.4rem;
  display: grid;
  place-items: center;
  color: var(--bone-paper);
  text-decoration: none;
  font-family: var(--mono);
  font-size: .66rem;
  border: 1px solid rgba(232, 223, 200, .2);
  background: rgba(5, 4, 3, .54);
  transform: rotate(45deg);
  transition: border-color 400ms ease, color 400ms ease, background 400ms ease;
}

.allotrope-nav a::before { content: attr(data-symbol); transform: rotate(-45deg); }
.allotrope-nav a span { position: absolute; right: 3.15rem; opacity: 0; white-space: nowrap; transform: rotate(-45deg) translateX(.6rem); color: var(--bone-paper); }
.allotrope-nav a:hover span { opacity: .86; }
.allotrope-nav a.active { color: var(--diamond-cyan); border-color: var(--diamond-cyan); background: rgba(143, 233, 255, .08); }

.chapter {
  position: relative;
  min-height: 100vh;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(2rem, 5vw, 5.5rem);
  display: grid;
  align-items: center;
}

.chapter::before {
  content: attr(data-chapter);
  position: absolute;
  left: clamp(1rem, 3vw, 3rem);
  top: clamp(1rem, 3vw, 3rem);
  font: 500 .72rem/1 var(--mono);
  letter-spacing: .28em;
  color: rgba(232, 223, 200, .42);
  z-index: 1;
}

.chapter::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: var(--scene, .2);
  transition: opacity 900ms ease;
}

.chapter.active { --scene: 1; }
.mono { font-family: var(--mono); letter-spacing: .16em; text-transform: uppercase; font-size: .72rem; color: rgba(232, 223, 200, .68); }
h1, h2 { font-family: var(--serif); font-weight: 400; margin: 0; line-height: .88; }
h2 { font-size: clamp(4rem, 12vw, 11rem); letter-spacing: -.04em; }
p { max-width: 38rem; font-size: clamp(1rem, 1.7vw, 1.38rem); line-height: 1.55; color: rgba(232, 223, 200, .78); }

.soot { background: var(--carbon-black); }
.soot::after { background: radial-gradient(circle at var(--mx) var(--my), rgba(232,223,200,.11), transparent 20rem), radial-gradient(circle at 72% 32%, rgba(48,34,57,.35), transparent 32rem); }
.specimen-label { position: absolute; top: 2rem; right: 8rem; max-width: 26rem; font-family: var(--mono); font-size: .68rem; letter-spacing: .18em; text-transform: uppercase; color: rgba(232,223,200,.45); border-top: 1px solid rgba(232,223,200,.25); padding-top: .65rem; }
.registration { position: absolute; width: 10rem; height: 10rem; border: 1px solid rgba(232,223,200,.12); }
.registration::before, .registration::after { content: ""; position: absolute; background: rgba(232,223,200,.24); }
.registration::before { width: 100%; height: 1px; top: 50%; left: 0; }
.registration::after { width: 1px; height: 100%; left: 50%; top: 0; }
.registration-a { left: 11vw; top: 12vh; transform: rotate(12deg); }
.soot-cloud { position: absolute; inset: 10% 4% 2% 0; background: radial-gradient(circle at 18% 70%, rgba(232,223,200,.13), transparent 7rem), radial-gradient(circle at 26% 74%, rgba(43,45,47,.82), transparent 18rem), radial-gradient(circle at 38% 58%, rgba(48,34,57,.42), transparent 19rem); filter: blur(2px); mix-blend-mode: screen; opacity: .7; }
.lower-left { align-self: end; margin: 0 0 8vh 4vw; }
.wordmark { position: relative; font-size: clamp(5.6rem, 20vw, 20rem); letter-spacing: .11em; color: rgba(232,223,200, calc(.11 + var(--pressure) * .68)); text-shadow: calc(var(--pressure) * 7px) 0 rgba(143,233,255,.14), calc(var(--pressure) * -10px) 6px rgba(228,87,30,.1); transition: color 600ms ease; }
.wordmark::after { content: attr(data-text); position: absolute; inset: .04em auto auto .045em; color: rgba(48,34,57,.75); z-index: -1; }
.prompt { font-family: var(--mono); letter-spacing: .22em; text-transform: uppercase; color: var(--diamond-cyan); }
.rub-plate { position: absolute; right: 12vw; bottom: 13vh; width: 18rem; height: 18rem; border-radius: 50%; border: 1px solid rgba(232,223,200,.16); display: grid; place-items: center; font-family: var(--mono); letter-spacing: .16em; text-transform: uppercase; color: rgba(232,223,200,.5); background: radial-gradient(circle, rgba(232,223,200,.06), transparent 68%); }

.graphite { background: linear-gradient(112deg, var(--carbon-black) 0 53%, #0c0b0a 53% 100%); }
.graphite::after { background: linear-gradient(96deg, transparent 0 42%, rgba(232,223,200,.08) 42% 46%, transparent 46%), radial-gradient(circle at 76% 28%, rgba(43,45,47,.8), transparent 26rem); }
.chapter-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 4vw; align-items: center; width: min(1180px, 92vw); margin: auto; }
.drawer { border-left: 1px solid rgba(232,223,200,.24); padding: 2rem 0 2rem 2rem; }
.graphite-rubbing { min-height: 72vh; position: relative; background: linear-gradient(90deg, rgba(232,223,200,.055), transparent 22%), repeating-linear-gradient(174deg, rgba(232,223,200,.06) 0 2px, transparent 2px 13px); border: 1px solid rgba(232,223,200,.12); box-shadow: inset 0 0 7rem rgba(5,4,3,.85); }
.thumbprint { position: absolute; width: 21rem; height: 27rem; right: 9%; top: 10%; border-radius: 47% 53% 45% 55%; background: repeating-radial-gradient(ellipse at 50% 50%, transparent 0 12px, rgba(232,223,200,.13) 13px 15px), radial-gradient(ellipse, rgba(43,45,47,.9), transparent 65%); transform: rotate(-13deg); opacity: .72; }
.pencil-lines { position: absolute; left: 8%; right: 14%; bottom: 16%; height: 36%; background: repeating-linear-gradient(166deg, rgba(232,223,200,.34) 0 1px, transparent 1px 8px); mask-image: linear-gradient(90deg, transparent, #000 18%, #000 72%, transparent); opacity: .5; }

.copy { background: radial-gradient(circle at 20% 20%, rgba(143,233,255,.08), transparent 24rem), var(--carbon-black); justify-items: center; }
.copy-sheet { position: relative; width: min(920px, 82vw); min-height: 68vh; padding: clamp(2rem, 5vw, 4.5rem); background: linear-gradient(100deg, rgba(232,223,200,.9), rgba(232,223,200,.72)); color: var(--carbon-black); box-shadow: 1.2rem 1.2rem 0 rgba(48,34,57,.55), -1rem -.8rem 0 rgba(138,75,42,.36); transform: rotate(-1.2deg); }
.copy-sheet h2 { color: rgba(5,4,3,.86); letter-spacing: .08em; font-size: clamp(5rem, 15vw, 15rem); }
.copy-sheet h2::after { content: attr(data-shadow); display: block; margin-top: -0.72em; color: rgba(143,233,255,.35); transform: translate(16px, 10px); mix-blend-mode: multiply; }
.copy-sheet p, .copy-sheet .mono { color: rgba(5,4,3,.7); }
.crop { position: absolute; width: 2.1rem; height: 2.1rem; border-color: var(--carbon-black); opacity: .55; }
.top-left { left: 1rem; top: 1rem; border-left: 2px solid; border-top: 2px solid; } .top-right { right: 1rem; top: 1rem; border-right: 2px solid; border-top: 2px solid; } .bottom-left { left: 1rem; bottom: 1rem; border-left: 2px solid; border-bottom: 2px solid; } .bottom-right { right: 1rem; bottom: 1rem; border-right: 2px solid; border-bottom: 2px solid; }
.transfer-ghost { position: absolute; font-family: var(--serif); color: rgba(143,233,255,.13); font-size: 40vw; line-height: 1; }
.ghost-one { left: -4vw; bottom: -12vw; } .ghost-two { right: 6vw; top: -7vw; color: rgba(48,34,57,.32); }

.lattice { background: radial-gradient(circle at 26% 52%, rgba(143,233,255,.12), transparent 29rem), var(--carbon-black); grid-template-columns: 1fr 1fr; gap: 4vw; }
.lens { position: relative; width: min(58vw, 720px); aspect-ratio: 1.15; border-radius: 50%; border: 1px solid rgba(143,233,255,.28); background: radial-gradient(circle, rgba(143,233,255,.08), rgba(43,45,47,.22) 38%, transparent 68%); display: grid; place-items: center; box-shadow: inset 0 0 6rem rgba(143,233,255,.06), 0 0 5rem rgba(48,34,57,.35); }
.hex-lattice { width: 92%; color: var(--diamond-cyan); filter: drop-shadow(0 0 12px rgba(143,233,255,.5)); }
.nodes circle { transform-origin: center; animation: nodeLock 4s ease-in-out infinite alternate; }
.bonds path { stroke-dasharray: 520; stroke-dashoffset: calc(260px - var(--pressure) * 260px); transition: stroke-dashoffset 700ms ease; }
.gauge { position: absolute; right: 9%; bottom: 10%; width: 8rem; height: 8rem; border-radius: 50%; border: 1px solid rgba(232,223,200,.25); }
.gauge span { position: absolute; width: 1px; height: 3.4rem; background: var(--ember-orange); left: 50%; bottom: 50%; transform-origin: bottom center; transform: rotate(calc(-45deg + var(--pressure) * 95deg)); box-shadow: 0 0 12px var(--ember-orange); }
.right-block { justify-self: start; }

.furnace { background: radial-gradient(ellipse at 50% 54%, rgba(228,87,30,.24), transparent 24rem), radial-gradient(circle at 50% 50%, rgba(138,75,42,.2), transparent 38rem), var(--carbon-black); justify-items: center; text-align: center; }
.furnace-mouth { position: absolute; width: min(76vw, 920px); height: 42vh; border-radius: 50%; background: radial-gradient(ellipse at center, var(--ember-orange) 0 8%, rgba(228,87,30,.52) 18%, rgba(138,75,42,.22) 38%, rgba(5,4,3,.95) 70%); filter: blur(.2px); box-shadow: inset 0 0 5rem #050403, 0 0 7rem rgba(228,87,30,.26); }
.furnace-mouth span { position: absolute; inset: 24% 10%; border-radius: 50%; background: radial-gradient(ellipse, rgba(232,223,200,.7), rgba(228,87,30,.35) 28%, transparent 62%); animation: breathe 4.8s ease-in-out infinite; }
.scorch-ring { position: absolute; width: 86vw; height: 86vw; max-width: 900px; max-height: 900px; border-radius: 50%; border: 1px solid rgba(228,87,30,.2); box-shadow: 0 0 8rem rgba(228,87,30,.13); }
.heat-copy { position: relative; z-index: 1; margin-top: 42vh; }
.heat-copy h2 { text-shadow: 0 0 24px rgba(228,87,30,.35); }

.mark { background: radial-gradient(circle at 50% 48%, rgba(5,4,3,.25), transparent 18rem), linear-gradient(90deg, var(--carbon-black), #0a0705 48%, var(--carbon-black)); justify-items: center; }
.ink-seal { width: min(72vw, 560px); aspect-ratio: 1; border-radius: 50%; display: grid; place-items: center; text-align: center; background: radial-gradient(circle, rgba(5,4,3,.98) 0 48%, rgba(43,45,47,.78) 49% 51%, rgba(5,4,3,.94) 52%); border: 1px solid rgba(232,223,200,.18); box-shadow: 0 0 0 1.4rem rgba(5,4,3,.4), inset 0 0 6rem rgba(48,34,57,.72); transform: scale(calc(.94 + var(--pressure) * .06)); transition: transform 700ms ease; }
.ink-seal span { font-family: var(--serif); font-size: clamp(4rem, 12vw, 9rem); letter-spacing: .1em; color: var(--bone-paper); text-shadow: 10px 8px 0 rgba(48,34,57,.5); }
.ink-seal small { position: absolute; bottom: 27%; font-family: var(--mono); letter-spacing: .2em; color: rgba(232,223,200,.54); }
.final-strip { position: absolute; left: 6vw; bottom: 8vh; width: min(34rem, 82vw); padding: 1.4rem 1.6rem; background: rgba(232,223,200,.9); color: var(--carbon-black); transform: rotate(.8deg); box-shadow: -.7rem .7rem 0 rgba(138,75,42,.45); }
.final-strip h2 { font-size: clamp(2.8rem, 6vw, 5.4rem); color: var(--carbon-black); }
.final-strip p, .final-strip .mono { color: rgba(5,4,3,.72); }

@keyframes breathe { 0%, 100% { transform: scaleX(.88) scaleY(.62); opacity: .5; } 50% { transform: scaleX(1.05) scaleY(.8); opacity: .95; } }
@keyframes nodeLock { from { opacity: .38; } to { opacity: 1; } }

@media (max-width: 820px) {
  .allotrope-nav { right: .8rem; }
  .specimen-label { display: none; }
  .chapter { padding: 1.4rem; }
  .chapter-grid, .lattice { grid-template-columns: 1fr; }
  .graphite-rubbing { min-height: 46vh; }
  .lens { width: 92vw; }
  .final-strip { position: relative; left: auto; bottom: auto; margin-top: 2rem; }
}