a.reference.external.image-reference img {
  transition: filter 150ms ease-in-out;
}

a.reference.external.image-reference:hover img,
a.reference.external.image-reference:focus-visible img {
  filter: brightness(1.1);
}

@media (prefers-reduced-motion: reduce) {
  a.reference.external.image-reference img {
    transition: none;
  }
}