.ai-hero {
  position: relative;
  min-height: calc(100svh - var(--header-height));
  padding-top: clamp(72px, 8vw, 112px);
  padding-bottom: clamp(72px, 8vw, 112px);
  overflow: hidden;
  border-bottom: 1px solid var(--color-border);
}

.ai-hero::before {
  position: absolute;
  top: -240px;
  left: -180px;
  width: 680px;
  height: 680px;
  background: radial-gradient(circle, var(--color-accent-glow-soft), transparent 68%);
  border-radius: var(--radius-pill);
  content: "";
  pointer-events: none;
}

.ai-hero::after {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-border) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-border) 1px, transparent 1px);
  background-size: 68px 68px;
  content: "";
  mask-image: linear-gradient(to bottom, transparent, var(--color-bg), transparent);
  opacity: .18;
  pointer-events: none;
}

.ai-hero-orbit {
  position: absolute;
  top: 50%;
  right: -110px;
  z-index: 0;
  width: min(52vw, 760px);
  color: var(--color-accent);
  opacity: .32;
  transform: translateY(-50%);
  pointer-events: none;
}

.ai-hero-orbit svg {
  width: 100%;
}

.ai-route {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
}

.ai-route-muted {
  color: var(--color-line);
}

.ai-route-inner {
  opacity: .55;
}

.ai-core-halo {
  fill: var(--color-accent-glow-soft);
  stroke: var(--color-accent);
  stroke-width: 1;
}

.ai-core {
  fill: var(--color-panel-raised);
  stroke: var(--color-accent);
  stroke-width: 1.5;
}

.ai-core-mark {
  fill: none;
  stroke: var(--color-accent);
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 5;
}

.ai-route-node {
  fill: var(--color-accent);
  stroke: var(--color-bg);
  stroke-width: 4;
}

.ai-hero-layout {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(330px, .75fr);
  gap: clamp(42px, 7vw, 100px);
  align-items: center;
}

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

.ai-hero-copy h1 {
  max-width: 720px;
  margin-top: 22px;
}

.ai-hero-copy .lead {
  max-width: 680px;
}

.ai-hero-copy .button-row {
  margin-top: 30px;
}

.ai-fact-row {
  display: flex;
  margin-top: 28px;
  flex-wrap: wrap;
  gap: 9px;
}

.ai-signup-note {
  max-width: 680px;
  margin: 18px 0 0;
  color: var(--color-text-muted);
  font-size: .86rem;
}

.ai-signal-panel {
  position: relative;
  padding: 26px;
  background: var(--color-panel);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-panel);
}

.ai-signal-panel::before {
  position: absolute;
  inset: -1px;
  z-index: -1;
  border: 1px solid var(--color-accent-deep);
  border-radius: var(--radius-lg);
  content: "";
  opacity: .3;
  filter: blur(5px);
}

.ai-signal-head {
  display: flex;
  margin-bottom: 6px;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border);
}

.ai-signal-head .eyebrow {
  margin-bottom: 14px;
}

.ai-path-step {
  position: relative;
  padding: 22px 0 20px 54px;
  border-bottom: 1px solid var(--color-border);
}

.ai-path-step:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.ai-path-step::before {
  position: absolute;
  top: 29px;
  left: 17px;
  width: 8px;
  height: 8px;
  background: var(--color-accent);
  border-radius: var(--radius-pill);
  box-shadow: 0 0 16px var(--color-accent-glow-strong);
  content: "";
}

.ai-path-step:not(:last-child)::after {
  position: absolute;
  top: 37px;
  bottom: -8px;
  left: 20px;
  width: 1px;
  background: var(--color-line);
  content: "";
}

.ai-path-key {
  display: block;
  margin-bottom: 5px;
  color: var(--color-accent-deep);
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .12em;
}

.ai-path-step strong {
  display: block;
  color: var(--color-text);
}

.ai-path-step p {
  margin: 7px 0 0;
  color: var(--color-text-muted);
  font-size: .84rem;
  line-height: 1.7;
}

.ai-article {
  padding-top: 56px;
  padding-bottom: var(--section-space);
}

.ai-chapter {
  padding-top: clamp(72px, 8vw, 108px);
  padding-bottom: clamp(72px, 8vw, 108px);
  border-bottom: 1px solid var(--color-border);
}

.ai-chapter:last-child {
  border-bottom: 0;
}

.ai-chapter-heading {
  display: grid;
  max-width: 1040px;
  margin-bottom: 42px;
  grid-template-columns: minmax(0, .8fr) minmax(300px, 1.2fr);
  gap: 10px 48px;
  align-items: start;
}

.ai-chapter-heading .eyebrow {
  grid-column: 1 / -1;
}

.ai-chapter-heading h2 {
  margin-bottom: 0;
}

.ai-chapter-heading > p:last-child {
  margin-bottom: 0;
  color: var(--color-text-muted);
  line-height: 1.85;
}

.ai-requirement-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--color-border);
  border-left: 1px solid var(--color-border);
}

.ai-requirement {
  min-height: 280px;
  padding: clamp(24px, 4vw, 42px);
  background: var(--color-panel);
  border-right: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.ai-requirement:nth-child(even) {
  background: var(--color-panel-raised);
}

.ai-requirement-code {
  display: inline-block;
  margin-bottom: 36px;
  color: var(--color-accent-deep);
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .14em;
}

.ai-requirement h3 {
  font-size: 1.3rem;
}

.ai-requirement p {
  margin-bottom: 0;
  color: var(--color-text-muted);
  line-height: 1.85;
}

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

.ai-flow-item {
  display: grid;
  padding: 30px 0;
  grid-template-columns: 140px minmax(0, 760px);
  gap: 34px;
  border-bottom: 1px solid var(--color-border);
}

.ai-flow-label {
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .12em;
}

.ai-flow-item h3 {
  font-size: 1.2rem;
}

.ai-flow-item p {
  margin-bottom: 0;
  color: var(--color-text-muted);
  line-height: 1.85;
}

.ai-split-notes {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.ai-split-notes .panel {
  min-height: 360px;
}

.ai-split-notes ul {
  margin-bottom: 0;
  color: var(--color-text-muted);
  line-height: 1.85;
}

.ai-split-notes li + li {
  margin-top: 12px;
}

.ai-dev-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.ai-dev-card {
  min-height: 380px;
  padding: clamp(24px, 3vw, 34px);
  background: var(--color-panel);
}

.ai-dev-card:nth-child(2) {
  background: var(--color-panel-raised);
}

.ai-dev-icon {
  display: grid;
  width: 48px;
  height: 48px;
  margin-bottom: 50px;
  place-items: center;
  color: var(--color-accent);
  background: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
}

.ai-dev-icon svg {
  width: 24px;
  height: 24px;
}

.ai-dev-icon path {
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

.ai-dev-card h3 {
  font-size: 1.24rem;
}

.ai-dev-card p {
  margin-bottom: 0;
  color: var(--color-text-muted);
  line-height: 1.85;
}

.ai-config-sample {
  margin-top: 24px;
  padding: 24px;
  background: var(--color-panel-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.ai-config-title {
  display: flex;
  margin-bottom: 16px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  color: var(--color-text);
  font-weight: 750;
}

.ai-config-title .mono {
  color: var(--color-accent-deep);
  font-size: .68rem;
  letter-spacing: .12em;
}

.ai-config-sample pre {
  margin-bottom: 16px;
  background: var(--color-bg);
}

.ai-config-sample p {
  margin-bottom: 0;
  color: var(--color-text-muted);
  font-size: .84rem;
}

.ai-choice-grid {
  display: grid;
  gap: 12px;
}

.ai-choice {
  display: grid;
  padding: 24px;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 20px;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.ai-choice-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  color: var(--color-bg);
  background: var(--color-accent);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-weight: 800;
}

.ai-choice h3 {
  margin-bottom: 6px;
  font-size: 1.08rem;
}

.ai-choice p {
  margin-bottom: 0;
  color: var(--color-text-muted);
  line-height: 1.8;
}

.ai-final-panel {
  display: grid;
  margin-top: 36px;
  padding: clamp(26px, 4vw, 42px);
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 32px;
  align-items: center;
  background: var(--color-panel-raised);
  border: 1px solid var(--color-accent-deep);
  border-radius: var(--radius-lg);
  box-shadow: 0 0 32px var(--color-accent-glow-soft);
}

.ai-final-panel h3 {
  margin-bottom: 8px;
}

.ai-final-panel p {
  max-width: 720px;
  margin-bottom: 0;
  color: var(--color-text-muted);
}

@media (max-width: 1040px) {
  .ai-hero-layout {
    grid-template-columns: 1fr;
  }

  .ai-hero-orbit {
    top: auto;
    right: -140px;
    bottom: -80px;
    width: 680px;
    transform: none;
  }

  .ai-signal-panel {
    max-width: 680px;
  }

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

  .ai-dev-card {
    min-height: auto;
  }

  .ai-dev-icon {
    margin-bottom: 28px;
  }
}

@media (max-width: 768px) {
  .ai-hero {
    min-height: auto;
  }

  .ai-hero::after {
    background-size: 44px 44px;
  }

  .ai-hero-orbit {
    right: -230px;
    bottom: -30px;
    width: 560px;
    opacity: .18;
  }

  .ai-hero-copy .lead {
    font-size: 1rem;
  }

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

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

  .ai-requirement {
    min-height: auto;
  }

  .ai-requirement:nth-child(even) {
    background: var(--color-panel);
  }

  .ai-flow-item {
    grid-template-columns: 1fr;
    gap: 10px;
  }

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

@media (max-width: 640px) {
  .ai-hero {
    padding-top: 64px;
    padding-bottom: 64px;
  }

  .ai-signal-panel {
    padding: 20px;
  }

  .ai-path-step {
    padding-left: 42px;
  }

  .ai-path-step::before {
    left: 10px;
  }

  .ai-path-step:not(:last-child)::after {
    left: 13px;
  }

  .ai-article {
    padding-top: 34px;
  }

  .ai-chapter {
    padding-top: 72px;
    padding-bottom: 72px;
  }

  .ai-requirement,
  .ai-choice,
  .ai-config-sample {
    padding: 20px;
  }

  .ai-choice {
    grid-template-columns: 42px minmax(0, 1fr);
    gap: 14px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .ai-hero-orbit {
    transform: none;
  }
}