/* The lighter landing cut: paper notes over a quiet glass stage. */
body.landing-page {
  --landing-paper: #f3eee4;
  --landing-paper-deep: #e4dacb;
  --landing-ink: #2d2b2a;
  --landing-muted: #6d665d;
  --landing-line: rgba(45, 43, 42, 0.18);
  background:
    radial-gradient(circle at 50% 0%, rgba(255, 252, 244, 0.85), transparent 45rem),
    #d8cfc1;
  color: var(--landing-ink);
}

body.landing-page #glass3d {
  opacity: 0.7;
}

body.landing-page .site-header {
  background: rgba(243, 238, 228, 0.84);
  border-bottom-color: var(--landing-line);
  box-shadow: 0 4px 20px rgba(68, 54, 40, 0.08);
}

body.landing-page .brand { color: #2b4052; }
body.landing-page .brand span { color: #9a6a2f; }
body.landing-page .nav a { color: var(--landing-muted); }
body.landing-page .nav a.active,
body.landing-page .nav a:hover {
  color: #173d55;
  text-shadow: none;
}
body.landing-page .claim-pill {
  color: #a04c38;
  border-color: rgba(160, 76, 56, 0.28);
  background: rgba(160, 76, 56, 0.06);
}

body.landing-page .telemetry-hud,
body.landing-page .depth-navigator {
  background: rgba(243, 238, 228, 0.86);
  border-color: var(--landing-line);
  box-shadow: 0 10px 28px rgba(68, 54, 40, 0.12);
  color: var(--landing-muted);
}
body.landing-page .hud-val { color: #21627e; }
body.landing-page .hud-val.gold { color: #976525; }
body.landing-page .hud-val.ember { color: #a04c38; }
body.landing-page .hud-progress-bar { background: rgba(45, 43, 42, 0.13); }
body.landing-page .depth-btn { color: var(--landing-muted); }
body.landing-page .depth-btn:hover {
  color: #173d55;
  background: rgba(33, 98, 126, 0.1);
  border-color: rgba(33, 98, 126, 0.24);
}

body.landing-page .grain-overlay {
  opacity: 0.025;
}

body.landing-page .rabbit-card {
  background: rgba(243, 238, 228, 0.91);
  border-color: var(--landing-line);
  box-shadow:
    0 18px 46px rgba(68, 54, 40, 0.16),
    inset 0 1px 0 rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
body.landing-page .rabbit-card h2 { color: #283d4d; }
body.landing-page .rabbit-card p { color: var(--landing-ink); }
body.landing-page .rabbit-badge { color: #976525; }
body.landing-page .rabbit-hint {
  background: rgba(151, 101, 37, 0.08);
  border-color: rgba(151, 101, 37, 0.3);
  color: #80551f;
}
body.landing-page .intro-note__lead {
  font-size: 1rem;
  line-height: 1.55;
  color: #2e3439;
}

/* Concept atlas: a calm editorial pause between the gate and the deep strata. */
body.landing-page .concept-atlas {
  position: relative;
  z-index: 12;
  display: grid;
  grid-template-columns: minmax(14rem, 0.78fr) minmax(0, 1.22fr);
  gap: clamp(2rem, 6vw, 6rem);
  width: min(90rem, calc(100% - 2rem));
  min-height: 132vh;
  margin: 0 auto;
  padding: clamp(4rem, 12vh, 9rem) clamp(1.2rem, 5vw, 5rem);
  border: 1px solid rgba(80, 66, 52, 0.18);
  border-radius: 4px;
  background:
    linear-gradient(rgba(255, 255, 255, 0.24) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.18) 1px, transparent 1px),
    var(--landing-paper);
  background-size: 100% 2.2rem, 2.2rem 100%, auto;
  box-shadow:
    0 28px 70px rgba(68, 54, 40, 0.18),
    inset 0 1px 0 rgba(255, 255, 255, 0.7);
}
body.landing-page .concept-atlas__heading {
  align-self: start;
  position: sticky;
  top: 15vh;
  max-width: 20rem;
}
body.landing-page .concept-atlas__kicker,
body.landing-page .concept-atlas__source,
body.landing-page .concept-card__lens {
  display: block;
  font-family: "IBM Plex Mono", Menlo, monospace;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
body.landing-page .concept-atlas__kicker {
  margin-bottom: 1rem;
  color: #a04c38;
  font-size: 0.64rem;
}
body.landing-page .concept-atlas__heading h2 {
  color: #263d4c;
  font-size: clamp(2rem, 4.2vw, 4.6rem);
  font-weight: 500;
  letter-spacing: -0.055em;
  line-height: 0.96;
}
body.landing-page .concept-atlas__heading h2 em {
  color: #9a6a2f;
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 400;
}
body.landing-page .concept-atlas__heading p {
  max-width: 18rem;
  margin-top: 1.5rem;
  color: var(--landing-muted);
  font-size: 0.92rem;
}
body.landing-page .concept-atlas__source {
  margin-top: 3rem;
  color: #8b8175;
  font-size: 0.58rem;
  line-height: 1.5;
}
body.landing-page .concept-atlas__visuals {
  position: sticky;
  top: 14vh;
  height: min(54vh, 33rem);
  margin-bottom: 2rem;
}
body.landing-page .concept-visual {
  position: absolute;
  inset: 0 8% auto 0;
  margin: 0;
  opacity: 0.38;
  transform: translateY(1rem) rotate(2.2deg) scale(0.97);
  transition: opacity 0.45s ease, transform 0.45s ease;
  pointer-events: none;
}
body.landing-page .concept-visual:nth-child(2) { transform: translateY(1rem) rotate(-1.4deg) scale(0.97); }
body.landing-page .concept-visual:nth-child(3) { transform: translateY(1rem) rotate(0.6deg) scale(0.97); }
body.landing-page .concept-visual.is-active {
  z-index: 2;
  opacity: 1;
  transform: translateY(0) rotate(-0.8deg) scale(1);
}
body.landing-page .concept-visual img {
  display: block;
  width: 100%;
  height: clamp(15rem, 42vh, 27rem);
  object-fit: cover;
  border: 0.55rem solid #f8f4eb;
  border-bottom-width: 2.2rem;
  box-shadow: 0 22px 44px rgba(68, 54, 40, 0.22);
  filter: saturate(0.88) contrast(0.95) sepia(0.08);
}
body.landing-page .concept-visual figcaption {
  position: absolute;
  right: 1rem;
  bottom: 0.7rem;
  left: 1rem;
  color: #766b60;
  font-family: "IBM Plex Mono", Menlo, monospace;
  font-size: 0.58rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}
body.landing-page .concept-grid {
  display: grid;
  grid-column: 1 / -1;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
  align-self: start;
}
body.landing-page .concept-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.8rem;
  min-height: 10rem;
  padding: 1.2rem 1.25rem;
  border: 1px solid rgba(80, 66, 52, 0.17);
  background: rgba(255, 252, 245, 0.68);
  box-shadow: 0 8px 22px rgba(68, 54, 40, 0.06);
  transition: transform 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}
body.landing-page .concept-card.is-active,
body.landing-page .concept-card:hover {
  border-color: rgba(33, 98, 126, 0.42);
  box-shadow: 0 14px 30px rgba(68, 54, 40, 0.13);
  transform: translateY(-3px);
}
body.landing-page .concept-card__number {
  color: #a04c38;
  font-family: "IBM Plex Mono", Menlo, monospace;
  font-size: 0.7rem;
}
body.landing-page .concept-card__lens {
  margin-bottom: 0.35rem;
  color: #9a6a2f;
  font-size: 0.58rem;
}
body.landing-page .concept-card h3 {
  margin-bottom: 0.35rem;
  color: #283d4d;
  font-size: 1.2rem;
  font-weight: 500;
}
body.landing-page .concept-card p {
  color: #5d574f;
  font-size: 0.82rem;
  line-height: 1.55;
}
body.landing-page .concept-card--wide { grid-column: 1 / -1; }

@media (max-width: 820px) {
  body.landing-page .site-header { align-items: flex-start; }
  body.landing-page .claim-pill { display: none; }
  body.landing-page .concept-atlas {
    display: block;
    min-height: auto;
    padding-top: 5rem;
  }
  body.landing-page .concept-atlas__heading,
  body.landing-page .concept-atlas__visuals {
    position: relative;
    top: auto;
  }
  body.landing-page .concept-atlas__heading { max-width: 30rem; }
  body.landing-page .concept-atlas__visuals {
    height: 48vh;
    margin: 3rem 0 2rem;
  }
}

@media (max-width: 560px) {
  body.landing-page .concept-grid { grid-template-columns: 1fr; }
  body.landing-page .concept-card--wide { grid-column: auto; }
  body.landing-page .concept-visual { right: 0; }
  body.landing-page .concept-atlas { width: calc(100% - 1rem); }
  body.landing-page .concept-atlas__source { margin-top: 2rem; }
}

@media (prefers-reduced-motion: reduce) {
  body.landing-page #glass3d { opacity: 0.45; }
  body.landing-page .concept-visual,
  body.landing-page .concept-card {
    transition: none;
    transform: none;
  }
}