/* ACD cross-page continuity (UPGRADE_PLAN_2026-10-05.md Phase 4f, Datum). Declared only under
   prefers-reduced-motion: no-preference, so reduced motion and unsupported browsers navigate instantly.
   Only the datum line and the page title carry a view-transition name; the rest of the page swaps without a fade.
   The names are unique per page (one #scrollProgress, one h1). The mark joins after G5 (Phase 7). */
@media (prefers-reduced-motion: no-preference) {
  @view-transition { navigation: auto; }
  #scrollProgress { view-transition-name: datum-line; }
  h1 { view-transition-name: page-title; }
  ::view-transition-old(root), ::view-transition-new(root) { animation: none; mix-blend-mode: normal; }
  ::view-transition-group(datum-line), ::view-transition-group(page-title) { animation-duration: 420ms; animation-timing-function: cubic-bezier(.22,1,.36,1); }
}