/* Shared chapter identity, including small screens. */
.chapter-heading {
  --chapter-mark-width: 180px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--chapter-mark-width);
  column-gap: 30px;
  align-items: center;
  min-width: 0;
}
.chapter-heading > .eyebrow {
  grid-column: 1 / -1;
  grid-row: 1;
  margin: 0;
}
.chapter-heading > h1 {
  grid-column: 1;
  grid-row: 2;
  min-width: 0;
  max-width: none;
  overflow-wrap: anywhere;
}
.chapter-heading > .chapter-mark {
  grid-column: 2;
  grid-row: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--chapter-mark-width);
  height: auto;
  aspect-ratio: 5 / 3;
  min-width: 0;
  margin: 0;
  padding: 0;
  flex: none;
  color: var(--mint, var(--green, #7dffd3));
  opacity: .56;
  pointer-events: none;
  user-select: none;
}
.chapter-mark > img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  transform: none;
}
.chapter-heading > .chapter-mark--cube { opacity: .45; }
.chapter-mark--cube > svg {
  display: block;
  width: 50%;
  height: auto;
  max-height: 100%;
}
.chapter-heading > .chapter-mark--voice {
  justify-content: space-between;
  height: calc(var(--chapter-mark-width) * .49);
  aspect-ratio: auto;
  gap: 3px;
  opacity: .55;
}
.chapter-mark--voice > i {
  flex: 0 1 3px;
  min-width: 1px;
  border-radius: 4px;
}
/* Retain the existing chapter-specific heading fonts, text and section spacing. */
.hero.chapter-hero { display: block; }
.hero.chapter-hero .eyebrow { margin: 0 0 18px; }

@media (max-width: 1100px) {
  .chapter-heading { --chapter-mark-width: 144px; column-gap: 24px; }
}
@media (max-width: 700px) {
  .chapter-heading { --chapter-mark-width: 90px; column-gap: 16px; }
  .chapter-heading > .chapter-mark--voice { gap: 2px; }
}
@media (max-width: 400px) {
  .chapter-heading { --chapter-mark-width: 76px; column-gap: 12px; }
  .chapter-heading > .chapter-mark--voice { gap: 1px; }
}