.chapter-navigation { padding: 20px 16px 16px; border: 1px solid var(--rule); border-radius: 18px; background: rgba(27, 37, 50, 0.24); }
.chapter-heading { font-size: 21px; line-height: 1.4; font-weight: 600; padding: 0 12px 16px; }
.chapter-list { list-style: none; padding: 0; }
.chapter-item { border-top: 1px solid rgba(226, 236, 249, 0.12); }
.chapter-link { position: relative; display: flex; flex-direction: column; gap: 2px; justify-content: center; min-height: 76px; padding: 12px 34px 12px 12px; border-radius: 8px; text-decoration: none; }
.chapter-desk { color: var(--muted); font-size: 16px; line-height: 1.35; }
.chapter-label { font-size: 16px; line-height: 1.45; font-weight: 500; }
.chapter-arrow { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); font-size: 20px; }
.chapter-link[aria-current="page"] { background: rgba(225, 239, 248, 0.11); box-shadow: inset 3px 0 var(--accent); }
.chapter-link:hover { background: rgba(225, 239, 248, 0.08); }
.index-return { display: flex; justify-content: space-between; align-items: center; min-height: 48px; padding: 10px 12px; margin-top: 12px; font-size: 16px; color: var(--accent); }

@media (min-width: 821px) {
  .chapter-navigation { max-height: calc(100dvh - 48px); overflow-y: auto; scrollbar-width: thin; scrollbar-color: #8b9aaa transparent; }
}
@media (min-width: 570px) and (max-width: 820px) {
  .chapter-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 18px; }
}