Respect prefers-reduced-motion

The blunt instrument, which kills every transition and animation on the page:

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

Near-zero rather than none, so animationend and transitionend events still fire and code waiting on them doesn't hang.

In JavaScript, check before you start anything that moves:

const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches

The logo shuffle on this site skips itself when that is true.