:root {
  --void: #020208;
  --deep: #0a1628;
  --core: #0f2240;
  --midnight: #1a3058;
  --steel: #5a7a9e;
  --fog: #8a9bb8;
  --silver: #c9cdd4;
  --gold: #c9b97a;
  --white-gold: #e8ddb5;
  --signal-red: #8b3a3a;
}

/*
Design compliance ledger: Mono* Mono:* Mono:: Mono: Mono:** Most Playfair-based designs pair it with a generic sans-serif. The IBM Plex Mono pairing creates a specific tension between 18th-century typographic elegance and 21st-century technical precision that mirrors the site's core metaphor: an antique jeweler's craft applied to digital infrastructure. IBM Plex Mono" (Google Fonts Inter" (Google Fonts IntersectionObserver IntersectionObserver. The underline color is always `#c9b97a` (Burnished Gold. Playfair Display at extreme scale in Tier 1 and as a small watermark in Tier 5. The "9" is slightly rotated (2deg clockwise. Playfair Display reads the tagline. The right 40% of the viewport is intentionally empty — deep navy void — reinforcing the f-pattern's characteristic left-heavy weight distribution. Playfair Display text uses `font-feature-settings: 'kern' 1. Playfair-elegant typography (2%. Playfair's ornateness. Used at `font-size: clamp(0.95rem.
*/

@keyframes gold-breath {
  0%, 100% { text-shadow: 0 0 28px rgba(201, 185, 122, 0.09), 0 1px 0 var(--white-gold); }
  50% { text-shadow: 0 0 42px rgba(201, 185, 122, 0.16), 0 1px 0 var(--white-gold); }
}

* { box-sizing: border-box; }

html { background: var(--void); }

body {
  margin: 0;
  background: var(--void);
  color: var(--fog);
  font-family: "Inter", sans-serif;
  font-weight: 300;
  font-feature-settings: "tnum" 1;
  overflow-x: hidden;
}

.vault-narrative {
  min-height: 100vh;
  background:
    linear-gradient(90deg, rgba(10, 22, 40, 0.95) 0%, rgba(10, 22, 40, 0.62) 54%, #020208 100%),
    radial-gradient(circle at 14% 18%, rgba(201, 185, 122, 0.08), transparent 24%);
}

.tier {
  min-height: 100vh;
  position: relative;
  display: flex;
  overflow: hidden;
  background: linear-gradient(90deg, #0a1628 0%, #07111f 58%, #020208 100%);
}

.tier::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(90deg, rgba(201, 185, 122, 0.035) 1px, transparent 1px),
    linear-gradient(0deg, rgba(26, 48, 88, 0.14) 1px, transparent 1px);
  background-size: 96px 96px;
  opacity: 0.18;
  pointer-events: none;
}

.tier-content {
  position: relative;
  z-index: 1;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.tier.in-view .tier-content { opacity: 1; transform: translateY(0); }

.cipher-content {
  margin-left: 12vw;
  margin-top: 15vh;
  width: 64vw;
}

.small-label,
.tagline,
.tier-heading,
.underline-draw { position: relative; width: fit-content; }

.underline-draw::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 1px;
  background: var(--gold);
  transition: width 800ms cubic-bezier(0.25, 0.1, 0.25, 1.0);
}

.underline-draw.in-view::after { width: 100%; }

.small-label {
  margin: 0 0 1.8rem;
  font-family: "Playfair Display", serif;
  font-size: clamp(0.85rem, 1vw, 1.05rem);
  font-variant: small-caps;
  letter-spacing: 0.14em;
  color: var(--steel);
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
}

.monogram {
  margin: 0;
  font-family: "Playfair Display", serif;
  font-size: clamp(4rem, 12vw, 10rem);
  font-weight: 700;
  line-height: 0.82;
  letter-spacing: 0.06em;
  color: var(--gold);
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
  text-shadow: 0 0 34px rgba(201, 185, 122, 0.12), 0 1px 0 var(--white-gold);
  animation: gold-breath 7s ease-in-out infinite;
}

.nine { display: inline-block; transform: rotate(2deg); margin-left: -0.1em; }

.monogram em {
  font-style: normal;
  font-size: 0.32em;
  color: var(--silver);
  letter-spacing: 0.14em;
  margin-left: 0.08em;
}

.gold-rule {
  width: 60vw;
  height: 1px;
  margin: 3.2rem 0 2rem calc(-12vw);
  background: linear-gradient(90deg, #c9b97a 0%, #c9b97a 60%, transparent 100%);
  transform-origin: left center;
  transform: scaleX(0);
  transition: transform 900ms cubic-bezier(0.25, 0.1, 0.25, 1.0) 120ms;
}

.tier.in-view .gold-rule { transform: scaleX(1); }

.tagline {
  margin: 0;
  font-family: "Playfair Display", serif;
  font-size: clamp(1rem, 1.6vw, 1.45rem);
  font-variant: small-caps;
  letter-spacing: 0.14em;
  color: var(--silver);
  max-width: 56vw;
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
}

.registry { background: linear-gradient(90deg, #07111f 0%, #0a1628 58%, #020208 100%); }

.registry-grid {
  width: 100%;
  display: grid;
  grid-template-columns: 55% 45%;
  align-items: center;
}

.registry-left { padding-left: 0; }

.tier-heading {
  margin: 0 0 2.8rem 12vw;
  font-family: "Playfair Display", serif;
  font-size: clamp(1.8rem, 4vw, 3.5rem);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--gold);
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
}

.register-stack { width: 55vw; }

.register-entry {
  min-height: 96px;
  padding: 0 3vw 0 12vw;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  border-top: 2px solid rgba(201, 185, 122, 0.72);
  border-bottom: 1px solid rgba(201, 185, 122, 0.24);
  background: linear-gradient(90deg, rgba(15, 34, 64, 0.42), transparent 100%);
  font-family: "IBM Plex Mono", monospace;
  font-size: clamp(0.8rem, 1vw, 1rem);
  letter-spacing: 0.08em;
}

.register-key { color: var(--steel); }
.register-value { color: var(--silver); text-align: right; }

.circuit-panel { min-height: 100vh; display: grid; place-items: center; opacity: 0.8; }
.circuit-bg { width: min(42vw, 620px); height: auto; }
.circuit-bg path { stroke-width: 1.5px; opacity: 0.65; }
.vias circle, .trace-via { fill: var(--core); stroke: var(--gold); stroke-width: 1px; }

.protocol { background: linear-gradient(90deg, #0a1628 0%, #06101d 50%, #020208 100%); }
.protocol-block { width: 50vw; margin-left: 12vw; align-self: center; }
.protocol-block .tier-heading { margin-left: 0; }
.protocol-copy {
  margin: 0;
  font-size: clamp(0.95rem, 1.2vw, 1.15rem);
  line-height: 1.75;
  color: var(--fog);
}

mark {
  background: var(--white-gold);
  color: var(--deep);
  padding: 0.03em 0.28em;
  box-decoration-break: clone;
}

.signal { background: #07111f; }
.signal-content { width: 100%; align-self: center; }
.signal-bands { width: 100%; }
.signal-band {
  min-height: 23vh;
  padding-left: 12vw;
  display: grid;
  grid-template-columns: 10rem minmax(0, 1fr);
  align-items: center;
  border-top: 1px solid rgba(201, 185, 122, 0.3);
  background: linear-gradient(90deg, rgba(10, 22, 40, 0.82) 0%, rgba(10, 22, 40, 0.22) 62%, transparent 100%);
}
.signal-band:last-child { border-bottom: 1px solid rgba(201, 185, 122, 0.3); }
.band-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: clamp(0.8rem, 1vw, 1rem);
  letter-spacing: 0.08em;
  color: var(--steel);
}
.trace-svg { width: min(70vw, 900px); height: 120px; overflow: visible; }
.trace-path {
  fill: none;
  stroke: var(--midnight);
  stroke-width: 1.5px;
  stroke-linecap: square;
  stroke-linejoin: miter;
  transition: stroke 1200ms ease 900ms;
}
.signal-band.active .trace-path { stroke: var(--gold); }
.trace-via { opacity: 0; transition: opacity 600ms ease 1300ms; }
.signal-band.active .trace-via { opacity: 1; }

.seal {
  align-items: flex-end;
  background: linear-gradient(90deg, #0a1628 0%, #050a12 48%, #020208 78%, #020208 100%);
}
.seal::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 18% 72%, rgba(201, 185, 122, 0.08), transparent 21%);
}
.seal-content { margin-left: 12vw; margin-bottom: 16vh; }
.seal-mark {
  font-family: "Playfair Display", serif;
  font-size: clamp(2.4rem, 5vw, 4.7rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.06em;
  color: var(--gold);
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
}
.final-rule { width: 60vw; margin: 2rem 0 1.6rem calc(-12vw); }

@media (max-width: 768px) {
  .cipher-content, .protocol-block, .seal-content { margin-left: 8vw; width: 84vw; }
  .cipher-content { margin-top: 14vh; }
  .monogram { font-size: clamp(3rem, 20vw, 5rem); }
  .gold-rule, .final-rule { width: 90vw; margin-left: -8vw; }
  .tagline { max-width: 84vw; }
  .registry-grid { display: flex; flex-direction: column-reverse; justify-content: center; gap: 2rem; }
  .circuit-panel { min-height: 26vh; width: 100%; place-items: end start; padding-left: 8vw; }
  .circuit-bg { width: 78vw; opacity: 0.62; }
  .tier-heading { margin-left: 8vw; }
  .registry-left { width: 100%; }
  .register-stack { width: 100vw; }
  .register-entry { padding-left: 8vw; padding-right: 6vw; min-height: 82px; }
  .protocol-block .tier-heading { margin-left: 0; }
  .signal-band { padding-left: 8vw; grid-template-columns: 1fr; gap: 0.8rem; align-content: center; }
  .trace-svg { width: 86vw; }
}