/* Visibility Index Tree — decorative background, not a card stack. */
.hv2-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  min-height: 100svh;
  display: flex;
  align-items: center;
}

.hv2-hero .hv2-hero-grid {
  position: relative;
  z-index: 10;
  display: block;
  width: min(760px, 100%);
  margin-inline: auto;
  text-align: center;
}

html[lang="zh-Hans"] .hv2-hero .hv2-hero-grid {
  width: 100%;
  max-width: none;
}

html[lang="zh-Hans"] .hv2-hero .hv2-h1,
html[lang="zh-Hans"] .hv2-hero .hv2-hero-def,
html[lang="zh-Hans"] .hv2-hero .hv2-hero-support {
  max-width: none;
  white-space: nowrap;
}

html[lang="zh-Hans"] .hv2-hero .hv2-h1 {
  margin: 0;
  font-size: clamp(1.55rem, 2.5vw, 2.75rem);
  line-height: 1.2;
}

html[lang="zh-Hans"] .hv2-hero .hv2-hero-def {
  margin: 4px 0 0;
  font-size: clamp(0.95rem, 1.35vw, 1.2rem);
  line-height: 1.35;
}

html[lang="zh-Hans"] .hv2-hero .hv2-hero-support {
  margin: 1.15em 0 24px;
  font-size: clamp(0.9rem, 1.15vw, 1.05rem);
  line-height: 1.45;
}

@media (max-width: 900px) {
  html[lang="zh-Hans"] .hv2-hero .hv2-h1,
  html[lang="zh-Hans"] .hv2-hero .hv2-hero-def,
  html[lang="zh-Hans"] .hv2-hero .hv2-hero-support {
    white-space: normal;
  }
}

.hv2-hero .hv2-hero-cta {
  justify-content: center;
}

.vit-stage {
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  opacity: 1;
  transform-origin: 50% 42%;
}

.vit-stage svg {
  width: 100%;
  height: 100%;
  display: block;
}

.vit-edge {
  fill: none;
  stroke-linecap: round;
  stroke-width: 1;
  opacity: 0.22;
}

.vit-edge.is-search { stroke: #38bdf8; }
.vit-edge.is-answer { stroke: #8b5cf6; }
.vit-edge.is-system { stroke: #22d3ee; }

.vit-node {
  opacity: 0.28;
}

.vit-node.is-pending {
  opacity: 0;
}

.vit-node.is-root,
.vit-node.is-hot {
  opacity: 1;
}

.vit-node circle {
  fill: #070b14;
  stroke-width: 1.4;
}

.vit-node.is-search circle { stroke: #38bdf8; }
.vit-node.is-answer circle { stroke: #8b5cf6; }
.vit-node.is-root circle { stroke: #22d3ee; fill: #101a2c; }

.vit-node text {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: 0.04em;
}

.vit-node.is-search text { fill: #38bdf8; }
.vit-node.is-answer text { fill: #c4b5fd; }
.vit-node.is-root text { fill: #f8fafc; font-size: 12px; }

.vit-signal {
  opacity: 0;
}

@media (max-width: 760px) {
  .vit-node text { font-size: 10px; }
  .vit-stage { opacity: 0.55; }
}

@media (prefers-reduced-motion: reduce) {
  .vit-edge,
  .vit-node,
  .vit-signal {
    transition: none !important;
    animation: none !important;
  }
}