/* Shared public navigation: hide while progressing down the page, and return
   immediately as soon as the visitor scrolls back up. */
.site-header {
  position: fixed;
  transform: translateY(0);
  transition: transform .24s ease, background-color .24s ease;
  will-change: transform;
}

.site-header.is-scroll-hidden { transform: translateY(calc(-100% - 1px)); }

/* Releases starts with its header in normal flow; sticky preserves that
   spacing while allowing the same direction-aware reveal behavior. */
.releases-page .site-header { position: sticky; top: 0; }

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