#swirl-background-root {
  background: #000 url('/assets/swirl-still.png') center / cover no-repeat;
}
#swirl-background-root canvas { display: block; width: 100%; height: 100%; }
#swirl-background-root canvas[hidden] { display: none; }
@media (prefers-reduced-motion: reduce) {
  #swirl-background-root canvas { display: none; }
}