:root {
  --twin-bg: #101110;
  --twin-ivory: #f7f3ea;
  --twin-stone: #c2beb4;
  --twin-muted: #8f8d87;
  --twin-rule: rgba(247, 243, 234, .48);
  --twin-rule-soft: rgba(247, 243, 234, .16);
  --twin-rule-faint: rgba(247, 243, 234, .1);
  --twin-max: 90rem;
  --twin-pad: clamp(1.25rem, 4.5vw, 4.75rem);
}

.twin-page,
.twin-integration,
.twin-page *,
.twin-integration * { box-sizing: border-box; }

.twin-page,
.twin-integration {
  min-height: 100%;
  margin: 0;
  background: var(--twin-bg);
  color: var(--twin-ivory);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.twin-page h1,
.twin-page h2,
.twin-page h3,
.twin-page p,
.twin-page ul,
.twin-integration h1,
.twin-integration h2,
.twin-integration h3,
.twin-integration p,
.twin-integration ul { margin: 0; }

.twin-shell { width: min(100%, var(--twin-max)); margin-inline: auto; padding-inline: var(--twin-pad); }

.twin-topbar {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  padding-block: 1.2rem;
  border-bottom: 1px solid var(--twin-rule-soft);
  color: var(--twin-muted);
  font-size: .67rem;
  font-weight: 700;
  letter-spacing: .15em;
  line-height: 1.3;
  text-transform: uppercase;
}

.twin-topbar p:last-child { text-align: right; }

.twin-artifact {
  --system-center-x: 50%;
  --system-center-optical-correction: 0px;
  position: relative;
  min-height: 47rem;
  margin-top: clamp(1rem, 3vw, 3.5rem);
  isolation: isolate;
}

.twin-geometry {
  position: absolute;
  z-index: -1;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
  pointer-events: none;
}

.twin-geometry .orbit,
.twin-geometry .axis,
.twin-geometry .learning-line,
.twin-geometry .learning-cue,
.twin-geometry .feedback-cue {
  fill: none;
  stroke: var(--twin-rule);
  stroke-width: 1.15;
  vector-effect: non-scaling-stroke;
}

.twin-geometry .learning-cue {
  stroke-width: 1;
  opacity: .82;
}

.twin-geometry .feedback-cue {
  stroke-width: 1.1;
  stroke-dasharray: 2 5;
  opacity: .9;
}

.twin-geometry marker path { stroke: var(--twin-rule); }

.twin-geometry .axis-center {
  x1: var(--system-center-x);
  x2: var(--system-center-x);
}

.twin-geometry .orbit-upper { opacity: .72; }

.twin-geometry .orbit-soft {
  fill: none;
  stroke: var(--twin-rule-faint);
  stroke-width: .9;
  vector-effect: non-scaling-stroke;
}

.twin-geometry .feedback {
  fill: none;
  stroke: var(--twin-rule);
  stroke-width: 1.05;
  stroke-dasharray: 2 5;
  vector-effect: non-scaling-stroke;
}

.compact-geometry { display: none; }

.asset-core,
.orbit-copy,
.edge-rail,
.learning-field { position: absolute; z-index: 1; }

.asset-core {
  top: 23%;
  left: calc(var(--system-center-x) + var(--system-center-optical-correction));
  width: min(20rem, 25%);
  transform: translateX(-50%);
  text-align: center;
}

.system-center-wrapper {
  position: relative;
  left: 50%;
  width: max-content;
  transform: translateX(-50%);
  text-align: center;
}

.asset-core h1,
.asset-core h2 {
  margin: 0 0 1.25rem;
  font-size: clamp(1.85rem, 3.7vw, 3.6rem);
  font-weight: 500;
  letter-spacing: .08em;
  line-height: .9;
  text-transform: uppercase;
}

.asset-core h1 span,
.asset-core h2 span { display: block; }

.asset-core ul,
.orbit-copy ul,
.edge-rail ul {
  display: grid;
  gap: .65rem;
  padding: 0;
  list-style: none;
}

.asset-core li {
  padding-block: .48rem;
  border-top: 1px solid var(--twin-rule-soft);
  color: var(--twin-stone);
  font-size: .9rem;
  line-height: 1.2;
}

.asset-core li:last-child { border-bottom: 1px solid var(--twin-rule-soft); }

.orbit-copy {
  top: 34%;
  width: 19rem;
  text-align: center;
}

.orbit-risk { left: 20%; transform: translateX(-50%); }
.orbit-routing { right: 20%; transform: translateX(50%); }

.orbit-copy h2,
.edge-rail h2,
.learning-field h2 {
  color: var(--twin-ivory);
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .13em;
  line-height: 1.25;
  text-transform: uppercase;
}

.orbit-copy h2::after {
  display: block;
  width: 2.25rem;
  height: 1px;
  margin: 1rem auto 1.4rem;
  background: var(--twin-rule-faint);
  content: "";
}

.orbit-copy li {
  color: var(--twin-stone);
  font-size: 1rem;
  line-height: 1.2;
}

.edge-rail {
  top: 37%;
  width: 11rem;
}

.rail-ai { left: 4%; text-align: left; }
.rail-human { right: 4%; text-align: right; }
.rail-ai { opacity: .86; }
.rail-human { opacity: .92; }

.edge-rail h2 {
  padding-bottom: .8rem;
  border-bottom: 1px solid var(--twin-rule-faint);
  color: var(--twin-stone);
  font-size: .7rem;
}

.edge-rail ul { gap: .8rem; margin-top: 1.3rem; }
.edge-rail li { color: var(--twin-stone); font-size: .76rem; line-height: 1.2; }

.learning-field {
  right: 16%;
  bottom: 1.5rem;
  left: 16%;
  display: grid;
  grid-template-columns: 1fr 2fr;
  align-items: center;
  gap: 3rem;
  padding-top: 1.2rem;
  border-top: 0;
  text-align: left;
}

.learning-field h2 { color: var(--twin-stone); }
.learning-items { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); }
.learning-items span {
  display: block;
  padding-inline: 1.25rem;
  border-left: 1px solid var(--twin-rule-faint);
  color: var(--twin-stone);
  font-size: .88rem;
  line-height: 1.2;
}
.learning-items span:first-child { padding-left: 0; border-left: 0; }

.twin-principle,
.twin-caption {
  width: min(100%, var(--twin-max));
  margin: 0 auto;
  padding-inline: var(--twin-pad);
  color: var(--twin-muted);
  font-size: .74rem;
  line-height: 1.45;
}

.twin-principle { padding-bottom: .5rem; text-align: center; letter-spacing: .06em; }
.twin-caption { padding-bottom: 2rem; text-align: center; }

.twin-integration .integration-section { min-height: 100svh; display: grid; align-items: center; }
.twin-integration .integration-layout {
  display: grid;
  grid-template-columns: minmax(0, .78fr) minmax(0, 1.22fr);
  gap: clamp(2.5rem, 5vw, 5rem);
  align-items: center;
  padding-block: clamp(3rem, 7vw, 7rem);
}

.integration-copy .section-marker {
  color: var(--twin-muted);
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
}

.integration-copy h2 {
  max-width: 9ch;
  margin-top: 2rem;
  font-size: clamp(3.8rem, 6.7vw, 7.3rem);
  font-weight: 470;
  letter-spacing: -.065em;
  line-height: .91;
}

.integration-copy p:last-child {
  max-width: 27rem;
  margin-top: 3.25rem;
  color: var(--twin-muted);
  font-size: clamp(1rem, 1.25vw, 1.1rem);
  line-height: 1.6;
}

.integration-map { min-width: 0; }
.integration-meta {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: .95rem;
  border-bottom: 1px solid var(--twin-rule-soft);
  color: var(--twin-muted);
  font-size: .66rem;
  font-weight: 700;
  letter-spacing: .15em;
  text-transform: uppercase;
}
.integration-meta span:last-child { text-align: right; }
.integration-artifact { min-height: 43rem; margin-top: .5rem; }
.integration-artifact .asset-core { width: min(18rem, 30%); }
.integration-artifact .orbit-copy { width: 14rem; }
.integration-artifact .orbit-risk { left: 20%; }
.integration-artifact .orbit-routing { right: 20%; }
.integration-artifact .edge-rail { width: 9rem; }
.integration-artifact .rail-ai { left: 1%; }
.integration-artifact .rail-human { right: 1%; }
.integration-artifact .learning-field { right: 12%; left: 12%; grid-template-columns: 1fr 1.9fr; }

@media (max-width: 1100px) {
  .twin-artifact { min-height: 43rem; }
  .asset-core { width: 24%; }
  .orbit-copy { width: 15rem; }
  .orbit-risk { left: 19%; }
  .orbit-routing { right: 19%; }
  .edge-rail { width: 8rem; }
  .rail-ai { left: 1%; }
  .rail-human { right: 1%; }
  .learning-field { right: 13%; left: 13%; }
  .twin-integration .integration-layout { gap: 2.5rem; }
  .integration-copy h2 { font-size: clamp(3.4rem, 7vw, 6rem); }
}

@media (max-width: 900px) {
  .twin-topbar { padding-block: 1rem; }
  .twin-artifact,
  .integration-artifact {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    grid-template-rows: auto auto auto auto;
    gap: 2rem 1rem;
    min-height: 0;
    margin-top: 2.25rem;
  }

  .desktop-geometry { display: none; }
  .compact-geometry { display: block; }
  .asset-core,
  .orbit-copy,
  .edge-rail,
  .learning-field {
    position: relative;
    inset: auto;
    width: auto;
    transform: none;
  }

  .asset-core { grid-column: 1 / -1; grid-row: 1; width: min(19rem, 70%); margin-inline: auto; }
  .orbit-copy { top: auto; grid-row: 2; width: auto; }
  .orbit-risk { grid-column: 1; left: auto; }
  .orbit-routing { grid-column: 2; right: auto; }
  .edge-rail { top: auto; grid-row: 4; width: auto; }
  .rail-ai { grid-column: 1; left: auto; text-align: left; }
  .rail-human { grid-column: 2; right: auto; text-align: right; }
  .learning-field { grid-column: 1 / -1; grid-row: 3; display: block; margin: 0; padding-top: 1.2rem; }
  .learning-field h2 { text-align: center; }
  .learning-items { margin-top: 1rem; }

  .twin-integration .integration-section { display: block; }
  .twin-integration .integration-layout { grid-template-columns: 1fr; gap: 3rem; padding-block: 4rem 3rem; }
  .integration-copy h2 { max-width: 10ch; }
  .integration-copy p:last-child { margin-top: 2rem; }
  .integration-artifact { margin-top: 1rem; }

  /* Integration-specific desktop offsets must release when the evidence map
     becomes a semantic mobile stack. */
  .integration-artifact .asset-core { width: min(19rem, 70%); }
  .integration-artifact .orbit-copy,
  .integration-artifact .edge-rail { width: auto; }
  .integration-artifact .orbit-risk,
  .integration-artifact .orbit-routing,
  .integration-artifact .rail-ai,
  .integration-artifact .rail-human,
  .integration-artifact .learning-field { left: auto; right: auto; }
  .integration-artifact .learning-field { width: auto; }
}

@media (max-width: 620px) {
  .twin-topbar { display: block; }
  .twin-topbar p:last-child { margin-top: .65rem; text-align: left; }
  .twin-artifact,
  .integration-artifact {
    grid-template-columns: 1fr;
    gap: 1.8rem;
    margin-top: 2rem;
  }

  .asset-core { grid-column: 1; width: min(19rem, 100%); }
  .asset-core { order: 1; }
  .orbit-copy { grid-column: 1; grid-row: auto; }
  .orbit-copy { order: 2; }
  .orbit-risk,
  .orbit-routing { grid-column: 1; }
  .learning-field { grid-column: 1; grid-row: auto; }
  .learning-field { order: 3; }
  .edge-rail { grid-column: 1; grid-row: auto; }
  .edge-rail { order: 4; }
  .rail-ai,
  .rail-human { grid-column: 1; }
  .rail-human { text-align: left; }
  .learning-items { gap: .6rem; }
  .learning-items span { padding-inline: .7rem; font-size: .83rem; }
  .integration-meta { display: block; }
  .integration-meta span + span { display: block; margin-top: .6rem; }
  .integration-meta span:last-child { text-align: left; }
  .integration-copy h2 { max-width: 9ch; font-size: clamp(3.2rem, 15vw, 5rem); }
  .integration-copy p:last-child { max-width: 22rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}