/* ============================================================================
   authbg.css — "raining Atlas icons" canvas behind the auth pages
   (js/authbg.js, window.AtlasAuthBG). One <canvas> inserted as the FIRST child
   of .auth-page[data-auth-root]; every bit of motion is canvas-drawn, so there
   is NO CSS animation, NO filter and NO backdrop-filter here (PERF LAW safe
   inside #app) — nothing to gate on html[data-perf]/[data-anim].

   Stacking (all inside .auth-page, position:relative):
   • .auth-page::before aurora  — z0, paints under all children
   • .authbg-canvas             — z0 first child, above the aurora
   • .auth-page::after vignette — z0, paints over children (intended soft fade)
   • .auth-card-page / .eyefx-stage — z1, always on top + interactive
============================================================================ */
.authbg-canvas{position:absolute;inset:0;width:100%;height:100%;display:block;
  z-index:0;pointer-events:none}