.ai-hero {
  padding-top: clamp(52px, 8vw, 92px);
  padding-bottom: clamp(52px, 8vw, 88px);
  border-bottom: 1px solid var(--color-border);
  text-align: center;
}

.ai-title {
  max-width: 900px;
  margin: 22px auto 0;
}

.ai-lead {
  max-width: 820px;
  margin: 22px auto 0;
  color: var(--color-muted);
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.8;
}

.ai-lecture {
  width: min(920px, 100%);
  margin: 42px auto 0;
  padding: clamp(22px, 4vw, 44px);
  box-shadow: var(--shadow-card);
  text-align: left;
}

.ai-lecture-head {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding-bottom: 14px;
  border-bottom: 1px dashed var(--color-border);
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
}

.ai-equation {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: .22em;
  margin-top: 34px;
  font-family: var(--font-mono);
  font-size: clamp(68px, 9vw, 116px);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1;
}

.ai-equals {
  color: var(--color-muted);
  font-size: .68em;
}

.ai-multiply {
  color: var(--color-accent);
}

.ai-vector-row {
  display: flex;
  justify-content: center;
  gap: clamp(28px, 7vw, 84px);
  margin-top: 26px;
}

.ai-vector {
  display: grid;
  gap: 8px;
  min-width: 0;
}

.ai-vector svg {
  width: 100%;
  height: 18px;
}

.ai-vector-line {
  fill: none;
  stroke: var(--color-accent);
  stroke-width: 2;
}

.ai-vector-head {
  fill: var(--color-accent);
}

.ai-vector span {
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 12px;
}

.ai-vector b {
  color: var(--color-text);
}

.ai-equation-note {
  max-width: 700px;
  margin: 30px auto 0;
  color: var(--color-muted);
  font-size: 13px;
  text-align: center;
}

.ai-document {
  padding-top: clamp(42px, 7vw, 76px);
  padding-bottom: var(--section-space);
}

.ai-document .toc-tabs {
  width: min(1080px, 100%);
  margin-inline: auto;
}

.ai-article {
  width: min(var(--reading-max), 100%);
  margin: 0 auto;
}

.ai-section {
  padding-top: clamp(64px, 8vw, 96px);
  padding-bottom: 4px;
}

.ai-section .section-number {
  margin-bottom: 12px;
  color: var(--color-accent);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .14em;
}

.ai-section h2 {
  margin-bottom: 24px;
}

.ai-section > p {
  line-height: 1.9;
}

.ai-matrix td:first-child {
  color: var(--color-text);
  font-family: var(--font-mono);
  font-weight: 750;
}

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

.ai-note {
  display: grid;
  grid-template-columns: minmax(190px, .75fr) minmax(0, 1.35fr);
  gap: clamp(24px, 5vw, 62px);
  padding-top: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--color-border);
}

.ai-note h3 {
  margin: 0;
  font-size: 19px;
}

.ai-note p {
  margin: 0;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.85;
}

.ai-process {
  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-process section {
  min-width: 0;
  padding: 24px;
  border-right: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel);
}

.ai-process h3 {
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 17px;
}

.ai-process p {
  margin: 0;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.85;
}

.ai-failure-list {
  margin: 0;
  border-top: 1px solid var(--color-border);
}

.ai-failure-list div {
  display: grid;
  grid-template-columns: minmax(190px, .75fr) minmax(0, 1.35fr);
  gap: clamp(24px, 5vw, 62px);
  padding-top: 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
}

.ai-failure-list dt {
  color: var(--color-text);
  font-weight: 700;
}

.ai-failure-list dd {
  margin: 0;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.85;
}

.ai-next-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 34px;
}

.ai-next-link {
  display: grid;
  min-width: 0;
  gap: 8px;
  padding: 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-s);
  background: var(--color-panel);
  box-shadow: var(--shadow-button);
  text-decoration: none;
  transition: border-color var(--motion-fast), transform var(--motion-fast);
}

.ai-next-link:hover {
  border-color: var(--color-muted);
  transform: translateY(-2px);
}

.ai-next-link .mono {
  color: var(--color-accent);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .12em;
}

.ai-next-link strong {
  font-size: 18px;
}

.ai-next-link p {
  margin: 0;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.7;
}

@media (max-width: 768px) {
  .ai-lecture-head,
  .ai-vector-row {
    align-items: center;
    flex-direction: column;
  }

  .ai-lecture-head {
    align-items: flex-start;
    gap: 4px;
  }

  .ai-vector-row {
    gap: 18px;
  }

  .ai-vector {
    width: min(280px, 100%);
  }

  .ai-note,
  .ai-failure-list div {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
  }

  .ai-process,
  .ai-next-links {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 640px) {
  .ai-hero {
    padding-top: 38px;
  }

  .ai-lecture {
    padding: 20px;
  }

  .ai-equation {
    font-size: clamp(52px, 20vw, 76px);
  }

  .ai-section {
    padding-top: 58px;
  }

  .ai-process section,
  .ai-next-link {
    padding: 20px;
  }
}