/* ── Right Navigation（右側浮動大綱）── */
.right-nav {
  position: fixed;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 360px;
  max-height: 70vh;
  overflow-y: auto;
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  box-shadow: var(--card-shadow);
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
  scrollbar-width: thin;
}
.right-nav.visible { opacity: 1; pointer-events: auto; }
.right-nav-title {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted-2);
  margin-bottom: 0.5rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border);
}
.right-nav-list { list-style: none; margin: 0; padding: 0; }
.right-nav-list li { margin: 0; padding: 0; }
.right-nav-list a {
  display: block;
  font-size: 0.88rem;
  color: var(--muted);
  text-decoration: none;
  padding: 0.3rem 0.5rem;
  border-radius: 5px;
  border-left: 2px solid transparent;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  line-height: 1.4;
}
.right-nav-list a:hover { background: var(--accent-dim); color: var(--accent-text); }
.right-nav-list a.active { background: var(--accent-dim); color: var(--accent); border-left-color: var(--accent); font-weight: 600; }
@media (max-width: 1100px) { .right-nav { display: none; } }