.foil-mask {
  position: absolute;
  inset: 0;
  pointer-events: none;
  mix-blend-mode: color;
  opacity: 0.4;
  mask-repeat: no-repeat;
  mask-position: center;
  mask-size: contain;
  -webkit-mask-repeat: no-repeat;
  -webkit-mask-position: center;
  -webkit-mask-size: contain;
}
.foil-mask.foil-rainbow {
  background: linear-gradient(135deg, #b80000, #888a00, #159800, #002d70, #7c0052);
}