/* Cube-room v4: decorative 3D ceiling, side corners, and floor. All site links unchanged.
   Matches the original floating cube strokes and inherits both dark/light themes. */
.cube-room {
  position: fixed;
  inset: 0;
  z-index: 1; /* floating cubes behind, content/card buttons above */
  width: 100%;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  pointer-events: none;
  color: var(--cube-stroke);
  isolation: isolate;
}
.cube-room__drawing { width: 100%; height: 100%; display: block; overflow: hidden; }
.cube-room__drawing path { vector-effect: non-scaling-stroke; }
.cube-room__grid { fill: none; stroke: currentColor; stroke-width: 1px; opacity: .16; }
.cube-room__edges { fill: none; stroke: currentColor; stroke-width: 1.35px; opacity: .42; }
.cube-room__side-lines { fill: none; stroke: currentColor; stroke-width: 1px; opacity: .18; }
.cube-room__corners { fill: none; stroke: currentColor; stroke-width: 1.8px; opacity: .63; }
/* The original elements, particularly the logo, remain in front of the room. */
#background_div { position: relative; z-index: 2; }
/* White backgrounds need a lighter outline so the ceiling doesn't overpower content. */
body.theme-light .cube-room__grid { opacity: .13; }
body.theme-light .cube-room__edges { opacity: .30; }
body.theme-light .cube-room__side-lines { opacity: .14; }
body.theme-light .cube-room__corners { opacity: .46; }
/* On phone screens the rear wall's vertical sides would intersect link cards.
   Keep ceiling and floor perspective while softening the sides. */
@media (max-width: 600px) {
  .cube-room__side-lines { opacity: .055; }
  .cube-room__grid { opacity: .115; }
  .cube-room__edges { opacity: .29; }
  .cube-room__corners { opacity: .38; }
}
@media (prefers-contrast: more) {
  .cube-room__grid, .cube-room__side-lines { opacity: .06; }
  .cube-room__edges, .cube-room__corners { opacity: .19; }
}