.ai-page {
  background:
    radial-gradient(62% 38% at 24% 4%, var(--color-glow-strong), transparent 74%),
    linear-gradient(180deg, var(--color-glow) 0%, transparent 52%),
    var(--color-bg);
}

.ai-hero {
  padding-bottom: 72px;
}

.ai-hero::before {
  position: absolute;
  top: 0;
  left: 0;
  width: 56%;
  height: 72%;
  max-width: 100%;
  background: radial-gradient(circle at 42% 32%, var(--color-glow-strong), transparent 68%);
  content: "";
  pointer-events: none;
}

.ai-hero .hero-stage,
.ai-hero .hero-copy {
  position: relative;
}

.ai-hero .hero-title {
  max-width: 8em;
}

.ai-hero .hero-lede {
  margin-top: 0;
}

.flag-inline li > span {
  font-size: 18px;
  line-height: 1;
}

.ai-article {
  overflow-x: clip;
}

.ai-section-alt {
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel-strong);
}

.ai-principles {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.ai-principle {
  position: relative;
  min-height: 310px;
  padding: 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-highlight), var(--shadow-card);
}

.ai-principle::after {
  position: absolute;
  right: 28px;
  bottom: 24px;
  left: 28px;
  height: 1px;
  background: linear-gradient(90deg, var(--color-accent), transparent);
  content: "";
}

.ai-principle-mark {
  display: inline-flex;
  margin-bottom: 34px;
  color: var(--color-accent-dark);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.ai-principle h3 {
  font-size: 23px;
}

.ai-principle p {
  margin-bottom: 38px;
  color: var(--color-muted);
}

.ai-tool-table td {
  min-width: 170px;
  color: var(--color-muted);
}

.ai-tool-table td:first-child {
  min-width: 130px;
  color: var(--color-text);
}

.ai-table-note {
  margin: 18px 0 0;
  color: var(--color-muted);
  font-size: 14px;
}

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

.ai-tool-card {
  position: relative;
  padding: 30px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-highlight), var(--shadow-card);
  transition: transform 150ms ease, box-shadow 150ms ease;
}

.ai-tool-card:nth-child(3n + 1) {
  background: var(--color-surface);
}

.ai-tool-card:hover {
  transform: translateY(-2px);
  box-shadow: inset 0 1px 0 var(--color-highlight), 0 24px 50px -24px var(--color-shadow-accent-strong);
}

.ai-tool-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.ai-tool-head h3 {
  margin-bottom: 0;
}

.ai-tool-card p {
  color: var(--color-muted);
}

.ai-tool-card p:last-child {
  margin-bottom: 0;
}

.ai-flow-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.28fr);
  gap: 64px;
  align-items: start;
}

.ai-flow-intro {
  position: sticky;
  top: var(--toc-offset);
}

.ai-flow-intro p {
  color: var(--color-muted);
  font-size: 18px;
}

.ai-flow {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: ai-flow;
}

.ai-flow li {
  position: relative;
  min-height: 150px;
  padding: 26px 26px 26px 82px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-highlight);
  counter-increment: ai-flow;
}

.ai-flow li::before {
  position: absolute;
  top: 26px;
  left: 24px;
  display: inline-flex;
  width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-accent);
  border-radius: 50%;
  background: var(--color-accent-tint);
  color: var(--color-accent-dark);
  content: counter(ai-flow);
  font: 700 13px/1 var(--font-mono);
}

.ai-flow h3 {
  margin-bottom: 8px;
  font-size: 21px;
}

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

.ai-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-panel);
}

.ai-compare-side {
  padding: 38px;
  background: var(--color-surface);
}

.ai-compare-side.is-strong {
  border-left: 1px solid var(--color-border);
  background: var(--color-panel-strong);
}

.ai-compare-side h3 {
  margin-top: 22px;
}

.ai-compare-side p,
.ai-compare-side li {
  color: var(--color-muted);
}

.ai-compare-side ul {
  display: grid;
  gap: 10px;
  margin-bottom: 0;
}

.developer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.developer-card {
  min-height: 360px;
  padding: 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-highlight), var(--shadow-card);
}

.developer-card:nth-child(2) {
  background: var(--color-surface);
}

.developer-label {
  display: inline-flex;
  min-width: 54px;
  min-height: 28px;
  align-items: center;
  justify-content: center;
  margin-bottom: 32px;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-xs);
  background: var(--color-accent-tint);
  color: var(--color-accent-dark);
  font-size: 11px;
  font-weight: 700;
}

.developer-card p {
  color: var(--color-muted);
}

.symptom-list {
  display: grid;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-panel);
  box-shadow: var(--shadow-card);
}

.symptom-row {
  display: grid;
  grid-template-columns: minmax(220px, 0.72fr) minmax(0, 1.28fr);
  gap: 40px;
  padding: 30px;
  border-bottom: 1px solid var(--color-border);
}

.symptom-row:last-child {
  border-bottom: 0;
}

.symptom-row:nth-child(even) {
  background: var(--color-panel-strong);
}

.symptom-code {
  display: block;
  margin-bottom: 12px;
  color: var(--color-accent-dark);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.symptom-row h3 {
  margin-bottom: 0;
  font-size: 21px;
}

.symptom-row p {
  margin-bottom: 8px;
  color: var(--color-muted);
}

.symptom-row p:last-child {
  margin-bottom: 0;
}

.symptom-row strong {
  color: var(--color-text);
}

.selection-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 36px;
}

.selection-card {
  min-height: 250px;
  padding: 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-highlight);
}

.selection-card:nth-child(even) {
  background: var(--color-surface);
}

.selection-step {
  display: block;
  min-height: 26px;
  margin-bottom: 28px;
  color: var(--color-accent-dark);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.selection-card h3 {
  font-size: 20px;
}

.selection-card p {
  margin-bottom: 0;
  color: var(--color-muted);
}

.ai-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 40px;
  align-items: center;
  padding: 36px;
}

.ai-next h2 {
  font-size: clamp(30px, 3.4vw, 42px);
}

.ai-next p {
  max-width: 58em;
  color: var(--color-muted);
}

.ai-next .button-row {
  max-width: 230px;
  flex-direction: column;
  align-items: stretch;
}

.ai-next .btn {
  width: 100%;
}

@media (max-width: 1180px) {
  .ai-principles,
  .developer-grid {
    grid-template-columns: 1fr;
  }

  .ai-principle,
  .developer-card {
    min-height: 0;
  }

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

  .selection-card {
    min-height: 220px;
  }
}

@media (max-width: 900px) {
  .ai-flow-layout {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .ai-flow-intro {
    position: static;
  }

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

  .ai-next .button-row {
    max-width: none;
    flex-direction: row;
  }
}

@media (max-width: 768px) {
  .ai-hero {
    padding-bottom: 54px;
  }

  .ai-hero::before {
    width: 100%;
    height: 48%;
  }

  .ai-tool-grid,
  .ai-compare {
    grid-template-columns: 1fr;
  }

  .ai-compare-side.is-strong {
    border-top: 1px solid var(--color-border);
    border-left: 0;
  }

  .symptom-row {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .selection-grid {
    grid-template-columns: 1fr;
  }

  .selection-card {
    min-height: 0;
  }
}

@media (max-width: 640px) {
  .ai-principle,
  .ai-tool-card,
  .developer-card,
  .ai-compare-side,
  .symptom-row,
  .selection-card {
    padding: 22px;
  }

  .ai-flow li {
    padding: 22px 20px 22px 68px;
  }

  .ai-flow li::before {
    top: 22px;
    left: 18px;
    width: 34px;
    height: 34px;
  }

  .ai-next {
    padding: 24px;
  }

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

  .ai-tool-head {
    align-items: flex-start;
    flex-direction: column;
  }
}