.contents-nav {
  /* Reserve a header control instead of overlaying the reading surface. */
  position: fixed;
  top: 6px;
  right: calc(21px + env(safe-area-inset-right));
  z-index: 31;
  font-size: 13px;
}
.contents-nav__toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  width: 44px;
  min-width: 44px;
  height: 44px;
  min-height: 44px;
  padding: 0;
  border: 1px solid rgba(148, 216, 45, 0.36);
  border-radius: 12px;
  background: rgba(15, 19, 13, 0.94);
  color: #eef5e8;
  box-shadow: none;
  backdrop-filter: blur(16px);
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: border-color 160ms ease, background 160ms ease;
}

.contents-nav__toggle:hover,
.contents-nav__toggle[aria-expanded="true"] {
  border-color: var(--green-bright, #94d82d);
  background: #202c16;
}

.contents-nav__icon {
  display: grid;
  gap: 4px;
  width: 16px;
  padding-left: 5px;
  color: var(--green-bright, #94d82d);
}

.contents-nav__icon i {
  position: relative;
  display: block;
  height: 1px;
  border-radius: 1px;
  background: currentColor;
}

.contents-nav__icon i { width: 11px; }
.contents-nav__icon i::before {
  position: absolute;
  top: -1px;
  left: -5px;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: currentColor;
  content: "";
}

.contents-nav__panel {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  width: min(276px, calc(100vw - 32px));
  max-height: calc(100svh - 80px);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 15px 10px 11px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 18px;
  background: rgba(16, 19, 15, 0.98);
  box-shadow: 0 16px 55px rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(20px);
  scrollbar-width: thin;
  scrollbar-color: #415832 transparent;
}

.contents-nav__heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin: 0 10px 11px;
  color: var(--muted, #a5aaa3);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.contents-nav__position {
  color: var(--green-bright, #94d82d);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 10px;
  letter-spacing: 0;
}

.contents-nav__list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.contents-nav__link {
  display: flex;
  align-items: center;
  gap: 11px;
  min-height: 36px;
  padding: 7px 10px;
  border: 1px solid transparent;
  border-radius: 8px;
  color: #d3d8cf;
  font-size: 12px;
  line-height: 1.5;
  text-decoration: none;
}

.contents-nav__number {
  flex: 0 0 26px;
  color: #8a9483;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 9px;
}

.contents-nav__item--nested .contents-nav__link { padding-left: 22px; }
.contents-nav__item--nested .contents-nav__number { flex-basis: 25px; }
.contents-nav__link:hover { color: #fff; background: rgba(255, 255, 255, 0.055); }
.contents-nav__link[aria-current="location"] {
  border-color: rgba(148, 216, 45, 0.24);
  color: #ecffd9;
  background: rgba(118, 185, 0, 0.13);
}
.contents-nav__link[aria-current="location"] .contents-nav__number { color: var(--green-bright, #94d82d); }
.contents-nav__link:focus-visible { outline-offset: -2px; }

/* All navigation controls remain in the fixed 56px header. */
.contents-nav__toggle > span:last-child {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
@media (min-width: 1041px) {
  .nav-links { margin-right: 56px; }
}
@media (max-width: 1040px) {
  .contents-nav { right: calc(73px + env(safe-area-inset-right)); }
  .nav-toggle { display: block; }
  .nav-links {
    position: absolute;
    top: 55px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    margin-right: 0;
    max-height: calc(100svh - 55px - env(safe-area-inset-bottom));
    overflow-y: auto;
    overscroll-behavior-y: contain;
    scrollbar-width: thin;
    scrollbar-color: #415832 transparent;
    padding: 10px 21px 18px;
    border-bottom: 1px solid var(--line);
    background: rgba(8, 9, 8, 0.96);
  }
  .nav-links.is-open { display: flex; }
  .nav-links > * { flex-shrink: 0; }
  .nav-links a { width: 100%; padding: 12px 0; }
}

@media (prefers-reduced-motion: reduce) {
  .contents-nav__toggle { transition: none; }
}

@media print { .contents-nav { display: none; } }