.reference-table thead {
  position: sticky;
  top: var(--level-nav-height, 63px);
  z-index: 10;
  box-shadow: 0 2px 3px #182b381a;
}
.reference-table tr {
  scroll-margin-top: calc(var(--level-nav-height, 63px) + var(--level-head-height, 80px) + 8px);
}
.level-section {
  scroll-margin-top: calc(var(--level-nav-height, 63px) + 12px);
}
@media (max-width: 1000px) {
  :root { --level-nav-height: 120px; }
}
@media print {
  .reference-table thead { position: static; box-shadow: none; }
}