:root {
  --sgi-matrix-color: #ffa51a;
  --sgi-matrix-opacity: .46;
}
.sgi-matrix {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: var(--sgi-matrix-opacity);
  /* Leave the reading area quiet, like the supplied reference. */
  -webkit-mask-image: radial-gradient(ellipse at center, transparent 12%, #0008 55%, #000 90%);
  mask-image: radial-gradient(ellipse at center, transparent 12%, #0008 55%, #000 90%);
}
body[data-sgi-matrix] > :not(.sgi-matrix) {
  position: relative;
  z-index: 1;
}
@media (prefers-reduced-motion: reduce) {
  .sgi-matrix { opacity: .08; }
}