:root{
  --chapter-label-size:12px;
  --chapter-label-gap:18px;
  --chapter-title-size:clamp(24px,2.5vw,40px);
  --chapter-title-weight:700;
  --chapter-title-leading:1.08;
  --chapter-title-tracking:-.035em;
  --chapter-heading-font:"Microsoft YaHei","微软雅黑",Arial,sans-serif;
}

/*
  Shared chapter-heading contract.
  Scope intentionally excludes all body copy, imagery, grids and motion.
  Before changing this component for one page, confirm whether the change
  should cascade to every chapter that uses the same heading pattern.
*/
.chapter header.reveal>.kicker{
  margin-bottom:var(--chapter-label-gap);
  font-family:var(--chapter-heading-font);
  font-size:var(--chapter-label-size);
  font-weight:400;
  line-height:1.4;
  letter-spacing:.19em;
}

.chapter header.reveal>.section-title{
  font-family:var(--chapter-heading-font);
  font-size:var(--chapter-title-size);
  font-weight:var(--chapter-title-weight);
  line-height:var(--chapter-title-leading);
  letter-spacing:var(--chapter-title-tracking);
}