.ai-hero {
  position: relative;
  overflow-x: clip;
  border-bottom: 1px solid var(--color-border);
  padding-top: clamp(58px, 8vw, 104px);
  padding-bottom: clamp(62px, 9vw, 112px);
}

.ai-hero::before {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-border) 1px, var(--color-transparent) 1px),
    linear-gradient(90deg, var(--color-border) 1px, var(--color-transparent) 1px);
  background-size: 72px 72px;
  content: "";
  opacity: 0.16;
  pointer-events: none;
}

.ai-hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(420px, 1.08fr);
  align-items: center;
  gap: clamp(38px, 7vw, 88px);
}

.ai-hero-copy {
  position: relative;
  z-index: 2;
}

.ai-hero-copy h1 {
  max-width: 9em;
  margin-top: 24px;
  font-size: clamp(52px, 5vw, 64px);
}

.ai-hero-lead {
  max-width: 39em;
  margin-bottom: 0;
  color: var(--color-text-muted);
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.85;
}

.ai-route-panel {
  position: relative;
  min-height: 500px;
  overflow: hidden;
  padding: 24px;
}

.ai-route-grid {
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, var(--color-border) 0 1px, var(--color-transparent) 1px 28px),
    repeating-linear-gradient(90deg, var(--color-border) 0 1px, var(--color-transparent) 1px 28px);
  opacity: 0.3;
  pointer-events: none;
}

.ai-route-head,
.ai-route-foot {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
}

.ai-route-state {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.ai-route-stage {
  position: relative;
  z-index: 2;
  display: grid;
  min-height: 400px;
  grid-template-columns: minmax(112px, 0.72fr) minmax(100px, 1fr) minmax(150px, 1.15fr);
  align-items: center;
  gap: 14px;
}

.ai-route-origin {
  display: flex;
  flex-direction: column;
  align-items: center;
  color: var(--color-text);
  text-align: center;
}

.ai-route-origin-dot {
  position: relative;
  width: 42px;
  height: 42px;
  margin-bottom: 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel-raised);
  box-shadow: var(--glow-accent);
}

.ai-route-origin-dot::before {
  position: absolute;
  inset: 14px;
  border-radius: var(--radius-pill);
  background: var(--color-success);
  content: "";
}

.ai-route-origin strong {
  font-size: 14px;
}

.ai-route-origin small {
  margin-top: 5px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 9px;
  line-height: 1.5;
}

.ai-route-lines,
.ai-route-tools {
  display: grid;
  gap: 40px;
}

.ai-route-line {
  position: relative;
  display: block;
  height: 1px;
  background: var(--color-border);
}

.ai-route-line::before,
.ai-route-line::after {
  position: absolute;
  top: 50%;
  width: 7px;
  height: 7px;
  border-radius: var(--radius-pill);
  background: var(--color-text-muted);
  content: "";
  transform: translateY(-50%);
}

.ai-route-line::before {
  left: 0;
}

.ai-route-line::after {
  right: 0;
}

.ai-route-line.is-current {
  height: 2px;
  background: var(--color-accent-dark);
  box-shadow: var(--glow-accent);
}

.ai-route-line.is-current::before,
.ai-route-line.is-current::after {
  background: var(--color-accent);
}

.ai-route-tools span {
  display: flex;
  min-height: 38px;
  align-items: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  background: var(--color-panel-raised);
  padding: 8px 12px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 10px;
}

.ai-route-tools span.is-current {
  border-color: var(--color-accent-dark);
  color: var(--color-text);
  box-shadow: var(--glow-accent);
}

.ai-route-foot {
  justify-content: space-around;
}

.ai-reading {
  max-width: calc(var(--content-max) + (var(--gutter) * 2));
  padding-top: clamp(34px, 5vw, 58px);
  padding-bottom: var(--section-space);
}

.ai-reading > .toc-tabs {
  top: 12px;
}

.ai-section {
  border-bottom: 1px solid var(--color-border);
}

.ai-section .section-head p {
  color: var(--color-text-muted);
  font-size: 17px;
}

.ai-principle-grid,
.ai-routing-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.ai-principle-grid {
  margin-bottom: 28px;
}

.ai-principle-grid .card,
.ai-routing-list .card {
  background: var(--color-panel);
}

.ai-principle-grid p,
.ai-routing-list p {
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-card-index {
  display: inline-block;
  margin-bottom: 13px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
}

.ai-tool-notes {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
  margin-top: 38px;
}

.ai-tool-notes article {
  border-left: 1px solid var(--color-border);
  padding-left: 22px;
}

.ai-tool-notes h3 {
  font-size: 19px;
}

.ai-tool-notes p {
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-flow {
  border-top: 1px solid var(--color-border);
}

.ai-flow-step {
  display: grid;
  grid-template-columns: minmax(100px, 0.22fr) minmax(0, 1fr);
  gap: clamp(24px, 5vw, 74px);
  border-bottom: 1px solid var(--color-border);
  padding-top: 28px;
  padding-bottom: 28px;
}

.ai-flow-step > span {
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.13em;
}

.ai-flow-step h3 {
  font-size: 21px;
}

.ai-flow-step p {
  max-width: 52em;
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 28px;
}

.ai-split-panel {
  padding: clamp(24px, 4vw, 38px);
}

.ai-split-panel ul {
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-split-panel li {
  margin-bottom: 11px;
}

.ai-split-panel li:last-child {
  margin-bottom: 0;
}

.ai-dev-ledger {
  border-top: 1px solid var(--color-border);
}

.ai-dev-row {
  display: grid;
  grid-template-columns: minmax(170px, 0.34fr) minmax(0, 1fr);
  gap: clamp(24px, 5vw, 74px);
  border-bottom: 1px solid var(--color-border);
  padding-top: 30px;
  padding-bottom: 30px;
}

.ai-dev-row h3 {
  margin-bottom: 0;
}

.ai-dev-row p {
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-routing-list {
  margin-bottom: 28px;
}

.ai-link-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 30px;
  margin-top: 32px;
  padding: clamp(24px, 4vw, 38px);
}

.ai-link-panel h3 {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 400;
}

.ai-link-panel p {
  max-width: 52em;
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-link-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px;
}

.ai-reading > .promo-block {
  margin-top: var(--section-space);
}

@media (max-width: 1020px) {
  .ai-hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(360px, 0.9fr);
    gap: 34px;
  }

  .ai-route-panel {
    min-height: 450px;
  }

  .ai-route-stage {
    min-height: 350px;
    grid-template-columns: minmax(92px, 0.65fr) minmax(70px, 0.8fr) minmax(130px, 1fr);
  }

  .ai-principle-grid,
  .ai-routing-list {
    grid-template-columns: 1fr;
  }

  .ai-tool-notes {
    grid-template-columns: 1fr;
    gap: 22px;
  }
}

@media (max-width: 768px) {
  .ai-hero {
    padding-top: 44px;
    padding-bottom: 58px;
  }

  .ai-hero-grid {
    grid-template-columns: 1fr;
  }

  .ai-hero-copy h1 {
    font-size: clamp(28px, 9.4vw, 40px);
  }

  .ai-hero-lead {
    font-size: 16px;
  }

  .ai-route-panel {
    min-height: 220px;
    padding: 16px;
  }

  .ai-route-stage {
    min-height: 166px;
    grid-template-columns: 74px minmax(58px, 1fr) minmax(116px, 1.3fr);
    gap: 8px;
  }

  .ai-route-origin-dot {
    width: 32px;
    height: 32px;
    margin-bottom: 8px;
  }

  .ai-route-origin-dot::before {
    inset: 11px;
  }

  .ai-route-origin small,
  .ai-route-foot {
    display: none;
  }

  .ai-route-lines,
  .ai-route-tools {
    gap: 17px;
  }

  .ai-route-tools span {
    min-height: 28px;
    padding: 5px 7px;
    font-size: 8px;
  }

  .ai-reading {
    padding-top: 24px;
  }

  .ai-flow-step,
  .ai-dev-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .ai-split {
    grid-template-columns: 1fr;
  }

  .ai-link-panel {
    grid-template-columns: 1fr;
  }

  .ai-link-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 430px) {
  .ai-route-head {
    font-size: 8px;
  }

  .ai-route-origin strong {
    font-size: 11px;
  }

  .ai-route-tools span {
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
  }

  .ai-link-actions {
    align-items: stretch;
    flex-direction: column;
  }
}