/* Layer chapter — the drawing assembles, then lifts into strata. illustration_only. */
.layer-chapter {
  position: relative;
  height: 380vh;
  z-index: 12;
  pointer-events: auto;
}
.layer-stage {
  --chapter-p: 0;
  --chapter-separation: 0;
  position: sticky;
  top: 0;
  height: 100vh;
  display: grid;
  place-items: center;
  perspective: 1300px;
  overflow: hidden;
  background:
    radial-gradient(ellipse at 50% 42%, rgba(184, 243, 255, 0.05), transparent 60%),
    linear-gradient(180deg, rgba(4, 5, 10, 0) 0%, rgba(4, 5, 10, 0.88) 12%, rgba(4, 5, 10, 0.88) 88%, rgba(4, 5, 10, 0) 100%);
}
.layer-sheet {
  position: relative;
  width: min(74vh, 88vw);
  aspect-ratio: 1;
  transform-style: preserve-3d;
  transform:
    rotateX(calc(var(--chapter-separation) * 52deg))
    rotateZ(calc(var(--chapter-separation) * -6deg));
  transition: transform 0.1s linear;
}
.layer-sheet::before {
  content: "";
  position: absolute;
  inset: -4%;
  background:
    linear-gradient(160deg, #f4f0e8 0%, #e9e2d4 55%, #ddd2be 100%);
  border-radius: 4px;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.5) inset,
    0 30px 80px rgba(0, 0, 0, 0.55),
    0 0 0 1px rgba(40, 30, 20, 0.15);
  transform: translateZ(-6px);
}
.layer-svg {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  opacity: 0;
  transform: translateZ(calc(var(--layer-z) * var(--chapter-separation) * 2.6px));
  transition: opacity 0.15s linear;
  pointer-events: none;
}
.layer-svg svg {
  width: 100%;
  height: 100%;
  overflow: visible;
  filter: drop-shadow(0 6px 14px rgba(4, 5, 10, 0.35));
}
.layer-svg [data-landmark] {
  pointer-events: auto;
  transition: stroke 0.25s ease, filter 0.25s ease;
}
.layer-svg [data-landmark]:hover,
.layer-svg [data-landmark]:focus-visible {
  stroke: var(--tide) !important;
  filter: drop-shadow(0 0 6px rgba(30, 200, 255, 0.8));
  outline: none;
}
.layer-caption {
  position: absolute;
  bottom: 7vh;
  left: 50%;
  transform: translateX(-50%);
  font-family: "IBM Plex Mono", Menlo, monospace;
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
  padding: 0.4rem 0.9rem;
  border: 1px solid rgba(240, 195, 106, 0.3);
  border-radius: 99px;
  background: rgba(6, 10, 20, 0.72);
  backdrop-filter: blur(8px);
  white-space: nowrap;
}
.layer-title-card {
  position: absolute;
  top: 9vh;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
  pointer-events: none;
  opacity: calc(1 - var(--chapter-separation) * 1.6);
}
.layer-title-card h2 {
  font-size: clamp(1.5rem, 3.4vw, 2.6rem);
  font-weight: 500;
  color: var(--foam);
  letter-spacing: 0.02em;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.7);
}
.layer-title-card p {
  margin-top: 0.4rem;
  font-size: 0.8rem;
  color: var(--mute);
  letter-spacing: 0.06em;
}
.layer-evidence {
  position: absolute;
  top: 9vh;
  right: 4vw;
  width: min(84vw, 21rem);
  padding: 1rem 1.2rem;
  border-radius: 10px;
  background: rgba(8, 14, 28, 0.92);
  border: 1px solid var(--border-light);
  backdrop-filter: blur(16px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.55), 0 0 20px rgba(30, 200, 255, 0.12);
  font-size: 0.78rem;
  z-index: 5;
}
.layer-evidence .tag {
  display: block;
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ember);
  margin-bottom: 0.5rem;
}
.layer-evidence dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.3rem 0.7rem;
}
.layer-evidence dt { color: var(--mute); font-family: "IBM Plex Mono", monospace; font-size: 0.7rem; }
.layer-evidence dd { color: var(--ink); }

@media (max-width: 720px) {
  .layer-sheet { width: 92vw; }
  .layer-evidence { top: auto; bottom: 14vh; right: 50%; transform: translateX(50%); }
}
@media (prefers-reduced-motion: reduce) {
  .layer-chapter { height: auto; padding: 4rem 0; }
  .layer-stage { position: relative; height: auto; min-height: 100vh; }
  .layer-svg { position: relative; opacity: 1 !important; transform: none; }
  .layer-sheet { transform: none; aspect-ratio: auto; display: grid; gap: 1rem; }
}