/* Crop only the photographed light on the tabletop; exclude the prism itself. */
.grading-standard{
  position:relative;
  isolation:isolate;
  overflow:hidden;
  background-color:#0a1018;
  background-image:
    radial-gradient(ellipse 1000px 900px at 90% 350px,#29405735,transparent 80%),
    linear-gradient(180deg,#101923 0,#0b111a 1400px,#0a1018 2400px);
}
.grading-standard::before{
  content:'';
  position:absolute;
  z-index:-1;
  pointer-events:none;
  top:0;
  right:0;
  width:1100px;
  height:1300px;
  background:url('assets/standards-acrylic-photo.jpg') left -340px / 3000px 2000px no-repeat;
  filter:grayscale(1) brightness(.64);
  opacity:.46;
  mix-blend-mode:screen;
  mask-image:linear-gradient(90deg,transparent 0,#000 38%,#000 100%),linear-gradient(180deg,transparent 0,#000 16%,#000 55%,transparent 100%);
  mask-composite:intersect;
}
@media(max-width:800px){
  .grading-standard::before{
    top:0;
    right:-180px;
    width:900px;
    height:1000px;
    opacity:.28;
    mask-image:linear-gradient(90deg,transparent 0,#000 60%),linear-gradient(180deg,#000 0,#000 45%,transparent 100%);
  }
}