.chapters-main {
  max-width: var(--col-full);
  margin: 0 auto;
  padding-left: var(--s-5);
  padding-right: var(--s-5);
}

.chapters-shell {
  display: grid;
  grid-template-columns: minmax(280px, 390px) minmax(0, 1fr);
  gap: var(--s-7);
  align-items: start;
}

.chapters-index {
  position: sticky;
  top: calc(var(--s-7) + 24px);
}

.chapter-list {
  border-top: 1px solid var(--hairline-soft);
}

.chapter-entry {
  width: 100%;
  text-align: left;
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--hairline-soft);
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: var(--s-2) var(--s-4);
  padding: var(--s-4) 0;
  cursor: pointer;
  transition: background 0.15s ease, padding 0.15s ease;
}

.chapter-entry:hover,
.chapter-entry.is-active {
  background: color-mix(in oklch, var(--bone) 58%, transparent);
  margin: 0 calc(-1 * var(--s-3));
  padding-left: var(--s-3);
  padding-right: var(--s-3);
  border-radius: 8px;
}

.chapter-entry-num {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--claret);
  padding-top: 4px;
}

.chapter-entry-title {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 400;
  color: var(--ink);
  line-height: 1.25;
  font-variation-settings: "opsz" 40;
}

.chapter-entry-desc {
  grid-column: 2;
  font-family: var(--sans);
  font-size: 13px;
  color: var(--ink-mute);
  line-height: 1.45;
}

.chapter-entry-state {
  grid-column: 2;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-mute);
}

.chapter-entry--read .chapter-entry-state {
  color: var(--sage);
}

.chapter-reader {
  min-width: 0;
}

.reader-shell {
  background: var(--bone);
  border: 1px solid var(--hairline);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 24px 70px oklch(20% 0.02 30 / 0.08);
}

.reader-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-4);
  padding: var(--s-4) var(--s-5);
  border-bottom: 1px solid var(--hairline-soft);
  background: color-mix(in oklch, var(--parchment) 62%, var(--bone));
}

.reader-kicker {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  display: block;
  margin-bottom: 3px;
}

.reader-title {
  font-family: var(--serif);
  font-size: clamp(20px, 2vw, 28px);
  font-weight: 400;
  color: var(--ink);
  line-height: 1.1;
  font-variation-settings: "opsz" 48;
}

.reader-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
  justify-content: flex-end;
}

.reader-link,
.reader-mark {
  border: 1px solid var(--hairline);
  border-radius: 999px;
  background: transparent;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 500;
  line-height: 1;
  padding: 10px 14px;
  cursor: pointer;
}

.reader-mark.is-read {
  border-color: color-mix(in oklch, var(--sage) 42%, var(--hairline));
  color: color-mix(in oklch, var(--sage) 70%, var(--ink));
  background: color-mix(in oklch, var(--sage) 10%, var(--bone));
}

.reader-frame {
  display: block;
  width: 100%;
  height: min(78vh, 880px);
  border: 0;
  background: var(--parchment);
}

.reader-note {
  margin-top: var(--s-4);
  font-family: var(--sans);
  font-size: 13px;
  color: var(--ink-mute);
  line-height: 1.5;
}

@media (max-width: 980px) {
  .chapters-shell {
    grid-template-columns: 1fr;
  }

  .chapters-index {
    position: static;
  }

  .reader-frame {
    height: 76vh;
  }
}

@media (max-width: 600px) {
  .chapters-main {
    padding-left: var(--s-4);
    padding-right: var(--s-4);
  }

  .chapter-entry:hover,
  .chapter-entry.is-active {
    margin: 0;
    padding-left: 0;
    padding-right: 0;
    border-radius: 0;
  }

  .reader-bar {
    align-items: flex-start;
    flex-direction: column;
  }

  .reader-actions {
    justify-content: flex-start;
  }
}