/* Keep the main navigation visible at every scroll position. */
:root { --site-header-height: 77px; }
body { padding-top: var(--site-header-height); }
body.home-page { --site-header-height: 81px; }
.site-header, .interior-page .site-header {
  position: fixed;
  inset: 0 0 auto;
  width: 100%;
  z-index: 100;
}
body [id], .home-page [id], .interior-page [id] {
  scroll-margin-top: calc(var(--site-header-height) + 16px);
}
.subnav, .interior-page .subnav { top: var(--site-header-height); }
@media (min-width: 641px) {
  .interior-page [id] { scroll-margin-top: calc(var(--site-header-height) + 76px); }
}
@media (max-width: 900px) {
  body.home-page, body.interior-page { --site-header-height: 69px; }
  .nav.open .nav-links, .home-page .nav.open .nav-links, .interior-page .nav.open .nav-links {
    top: 100%;
    max-height: calc(100dvh - var(--site-header-height));
    overflow-y: auto;
  }
}
@media (max-width: 640px) {
  :root { --site-header-height: 69px; }
  .interior-page .subnav { top: 0; }
}