.ai-hero {
  position: relative;
  min-height: calc(100vh - var(--header-height));
  overflow: hidden;
  border-bottom: 2px solid var(--color-border);
  background:
    linear-gradient(var(--color-grid) 1px, var(--color-transparent) 1px),
    linear-gradient(90deg, var(--color-grid) 1px, var(--color-transparent) 1px),
    radial-gradient(circle at 76% 42%, var(--color-panel-glow), var(--color-transparent) 34%),
    var(--color-bg);
  background-size: 46px 46px, 46px 46px, auto, auto;
}

.ai-hero::after {
  position: absolute;
  right: -12%;
  bottom: -46%;
  width: 72%;
  height: 78%;
  content: "";
  border-top: 2px solid var(--color-grid-strong);
  background:
    repeating-linear-gradient(90deg, var(--color-transparent) 0 68px, var(--color-grid-strong) 69px 70px),
    repeating-linear-gradient(0deg, var(--color-transparent) 0 48px, var(--color-grid) 49px 50px);
  opacity: 0.72;
  transform: perspective(440px) rotateX(64deg);
  transform-origin: center top;
  pointer-events: none;
}

.ai-hero-grid {
  position: relative;
  z-index: 2;
  min-height: calc(100vh - var(--header-height));
  display: grid;
  grid-template-columns: minmax(430px, 0.82fr) minmax(560px, 1.18fr);
  align-items: center;
  gap: clamp(28px, 5vw, 76px);
  padding-top: 64px;
  padding-bottom: 64px;
}

.ai-hero-copy {
  position: relative;
  z-index: 3;
  padding-left: 22px;
}

.ai-hero-copy::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 4px;
  content: "";
  background: linear-gradient(to bottom, var(--color-accent), var(--color-accent) 62%, var(--color-border) 62%);
}

.ai-hero-copy h1 {
  max-width: 620px;
  margin-top: 20px;
}

.ai-hero-actions {
  margin-top: 30px;
}

.ai-hero-copy .lead {
  max-width: 650px;
  margin: 32px 0 0;
}

.ai-hero-note {
  max-width: 630px;
  margin: 18px 0 24px;
  color: var(--color-text-muted);
  font-size: 14px;
}

.ai-route-device {
  position: relative;
  min-height: 610px;
  isolation: isolate;
}

.ai-route-device::before {
  position: absolute;
  inset: 34px 0 28px 18px;
  z-index: -1;
  content: "";
  border: 2px solid var(--color-border);
  background:
    linear-gradient(135deg, var(--color-transparent) 0 var(--cut-medium), var(--color-panel) calc(var(--cut-medium) + 1px)) top left,
    linear-gradient(225deg, var(--color-transparent) 0 var(--cut-medium), var(--color-panel) calc(var(--cut-medium) + 1px)) top right,
    linear-gradient(45deg, var(--color-transparent) 0 var(--cut-medium), var(--color-panel) calc(var(--cut-medium) + 1px)) bottom left,
    linear-gradient(315deg, var(--color-transparent) 0 var(--cut-medium), var(--color-panel) calc(var(--cut-medium) + 1px)) bottom right;
  background-repeat: no-repeat;
  background-size: 51% 51%;
  box-shadow: 14px 14px 0 var(--color-black);
  opacity: 0.84;
  clip-path: polygon(var(--cut-medium) 0, calc(100% - var(--cut-medium)) 0, 100% var(--cut-medium), 100% calc(100% - var(--cut-medium)), calc(100% - var(--cut-medium)) 100%, var(--cut-medium) 100%, 0 calc(100% - var(--cut-medium)), 0 var(--cut-medium));
}

.ai-route-label {
  position: absolute;
  top: 54px;
  left: 44px;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 750;
  letter-spacing: 0.12em;
}

.ai-route-label::before {
  width: 36px;
  height: 3px;
  content: "";
  background: var(--color-accent);
}

.ai-route-svg {
  position: absolute;
  inset: 64px -28px 0 -24px;
  width: calc(100% + 52px);
  height: 520px;
  max-width: none;
}

.ai-gate-shadow,
.ai-gate-frame,
.ai-gate-inner,
.ai-grid-line,
.ai-route-underlay,
.ai-route-line,
.ai-route-dash,
.ai-exit-mark {
  fill: none;
}

.ai-gate-shadow {
  stroke: var(--color-black);
  stroke-width: 34;
  transform: translate(12px, 14px);
}

.ai-gate-frame {
  stroke: var(--color-border);
  stroke-width: 34;
}

.ai-gate-inner {
  stroke: var(--color-bg);
  stroke-width: 18;
}

.ai-grid-line {
  stroke: var(--color-border-bright);
  stroke-dasharray: 4 9;
  stroke-width: 2;
}

.ai-route-underlay {
  stroke: var(--color-black);
  stroke-linecap: square;
  stroke-linejoin: bevel;
  stroke-width: 18;
}

.ai-route-line {
  stroke: var(--color-accent);
  stroke-linecap: square;
  stroke-linejoin: bevel;
  stroke-width: 9;
}

.ai-route-dash {
  stroke: var(--color-text);
  stroke-dasharray: 15 18;
  stroke-width: 3;
}

.ai-node-box,
.ai-node-ring,
.ai-exit-box {
  fill: var(--color-bg);
  stroke: var(--color-border-bright);
  stroke-width: 3;
}

.ai-node-core {
  fill: var(--color-accent);
}

.ai-node-state {
  fill: var(--color-success);
  filter: drop-shadow(0 0 7px var(--color-success));
}

.ai-exit-mark {
  stroke: var(--color-success);
  stroke-linecap: square;
  stroke-linejoin: bevel;
  stroke-width: 4;
}

.ai-tool-label {
  fill: var(--color-panel);
  stroke: var(--color-border);
  stroke-width: 2;
}

.ai-tool-text {
  fill: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.ai-route-caption {
  position: absolute;
  right: 34px;
  bottom: 50px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
}

.ai-toc-host {
  position: relative;
  z-index: 20;
  padding-top: 24px;
}

.ai-article {
  overflow: clip;
}

.ai-section-layout {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 34px;
}

.ai-section-rail {
  display: flex;
  min-height: 100%;
  align-items: center;
  flex-direction: column;
  gap: 18px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.12em;
  writing-mode: vertical-rl;
}

.ai-rail-mark {
  width: 4px;
  min-height: 180px;
  flex: 1 1 auto;
  background:
    repeating-linear-gradient(to bottom, var(--color-accent) 0 24px, var(--color-border) 24px 48px);
}

.ai-content-panel {
  position: relative;
  padding: clamp(26px, 4vw, 48px);
  border: 2px solid var(--color-border);
  background: var(--color-panel);
  box-shadow: var(--shadow-hard);
  clip-path: polygon(0 0, calc(100% - var(--cut-medium)) 0, 100% var(--cut-medium), 100% 100%, var(--cut-medium) 100%, 0 calc(100% - var(--cut-medium)));
}

.ai-content-panel::before {
  position: absolute;
  top: -2px;
  left: 34px;
  width: 88px;
  height: 5px;
  content: "";
  background: var(--color-accent);
}

.ai-principle-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 18px;
}

.ai-principle {
  min-height: 250px;
  padding: 24px;
  border: 2px solid var(--color-border);
  background:
    linear-gradient(var(--color-grid) 1px, var(--color-transparent) 1px),
    linear-gradient(90deg, var(--color-grid) 1px, var(--color-transparent) 1px),
    var(--color-panel-strong);
  background-size: 28px 28px;
}

.ai-principle-wide {
  grid-row: span 2;
  min-height: 100%;
}

.ai-principle-code,
.ai-mode-label,
.ai-dev-code {
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.1em;
}

.ai-principle h3 {
  margin-top: 18px;
}

.ai-principle p,
.ai-mode-panel p,
.ai-dev-row p,
.ai-choice-card p {
  margin-bottom: 0;
  color: var(--color-text-muted);
}

.ai-table-note {
  margin: 24px 0 0;
  padding-left: 16px;
  border-left: 4px solid var(--color-accent);
  color: var(--color-text-muted);
}

.ai-flow {
  border-top: 2px solid var(--color-border);
}

.ai-flow-step {
  position: relative;
  display: grid;
  grid-template-columns: minmax(190px, 0.35fr) minmax(0, 0.65fr);
  gap: 32px;
  padding: 28px 0;
  border-bottom: 1px solid var(--color-border);
}

.ai-flow-step::before {
  position: absolute;
  top: 34px;
  left: -12px;
  width: 7px;
  height: 7px;
  content: "";
  background: var(--color-accent);
  transform: rotate(45deg);
}

.ai-flow-step h3,
.ai-flow-step p {
  margin-bottom: 0;
}

.ai-flow-step p {
  color: var(--color-text-muted);
}

.ai-mode-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.ai-mode-panel {
  min-height: 100%;
}

.ai-mode-panel h3 {
  margin-top: 14px;
}

.ai-dev-stack {
  border-top: 2px solid var(--color-border);
}

.ai-dev-row {
  display: grid;
  grid-template-columns: minmax(170px, 0.3fr) minmax(0, 0.7fr);
  align-items: start;
  gap: 32px;
  padding: 28px 0;
  border-bottom: 1px solid var(--color-border);
}

.ai-dev-row h3 {
  margin: 8px 0 0;
}

.ai-failure-list {
  border-top: 0;
  box-shadow: var(--shadow-hard);
}

.ai-choice-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.ai-choice-card {
  min-height: 290px;
}

.ai-choice-card h3 {
  margin-top: 24px;
}

.ai-link-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 30px;
  margin-top: 44px;
  padding: clamp(24px, 4vw, 38px);
  border: 2px solid var(--color-border-bright);
  background:
    linear-gradient(90deg, var(--color-accent-soft), var(--color-transparent)),
    var(--color-panel-strong);
  box-shadow: var(--shadow-hard);
}

.ai-link-panel h3 {
  margin: 8px 0;
}

.ai-link-panel p {
  max-width: 760px;
  margin-bottom: 0;
  color: var(--color-text-muted);
}

@media (max-width: 1120px) {
  .ai-hero-grid {
    grid-template-columns: minmax(390px, 0.9fr) minmax(470px, 1.1fr);
  }

  .ai-route-device {
    min-height: 560px;
  }

  .ai-route-svg {
    height: 490px;
  }

  .ai-choice-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ai-choice-card:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 980px) {
  .ai-hero {
    min-height: auto;
  }

  .ai-hero-grid {
    min-height: auto;
    grid-template-columns: 1fr;
    padding-top: 76px;
    padding-bottom: 58px;
  }

  .ai-hero-copy {
    max-width: 760px;
  }

  .ai-route-device {
    width: min(100%, 760px);
    min-height: 540px;
    margin-inline: auto;
  }

  .ai-section-layout {
    grid-template-columns: 48px minmax(0, 1fr);
    gap: 22px;
  }

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

  .ai-principle-wide {
    grid-row: auto;
  }

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

@media (max-width: 768px) {
  .ai-route-label,
  .ai-route-caption {
    display: none;
  }

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

  .ai-section-rail {
    display: none;
  }

  .ai-flow-step,
  .ai-dev-row {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .ai-flow-step::before {
    display: none;
  }

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

  .ai-choice-card:last-child {
    grid-column: auto;
  }
}

@media (max-width: 640px) {
  .ai-hero-grid {
    padding-top: 52px;
    padding-bottom: 42px;
  }

  .ai-hero-copy {
    padding-left: 14px;
  }

  .ai-hero-copy .lead {
    margin-top: 24px;
  }

  .ai-route-device {
    min-height: 390px;
  }

  .ai-route-device::before {
    inset: 16px 0 12px;
  }

  .ai-route-svg {
    inset: 8px -98px 0 -96px;
    width: calc(100% + 194px);
    height: 380px;
  }

  .ai-content-panel {
    padding: 20px;
    box-shadow: 5px 5px 0 var(--color-black);
  }

  .ai-principle {
    min-height: auto;
    padding: 20px;
  }

  .ai-link-panel .button-row {
    flex-direction: column;
  }

  .ai-link-panel .button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .ai-route-device,
  .ai-route-svg {
    transform: none;
  }
}