/* Stage 10D.3f — background is painted on a dedicated canvas.
   The expensive CSS ambient stack remains in swagball.css for compatibility,
   but no .ambient DOM tree is created by /app/. */
.ambient-canvas{
  position:fixed;
  inset:0;
  width:100vw;
  height:100vh;
  z-index:-3;
  display:block;
  pointer-events:none;
  background:#050711;
}
html[data-ambient-backend="static-css"] .ambient-canvas{
  background:
    radial-gradient(circle at 14% 16%,rgba(40,227,255,.13),transparent 31%),
    radial-gradient(circle at 86% 18%,rgba(139,75,255,.15),transparent 32%),
    radial-gradient(circle at 70% 80%,rgba(255,70,164,.11),transparent 31%),
    radial-gradient(circle at 18% 84%,rgba(255,176,82,.08),transparent 30%),
    linear-gradient(180deg,#060812 0%,#050711 55%,#03050a 100%);
}
@media(prefers-reduced-motion:reduce){
  .ambient-canvas{background:#050711}
}