/* The overlay contains exact copies of the colour master and high-resolution
   tiles. All grading belongs to the parent overlay, not to its image children. */
.reading-focus-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  isolation: isolate;
  transition: none;
}

/* Reset historical per-image brightness: neutral grading applies exactly once
   to the copied source. Keep the source's light and tree detail in grayscale;
   do not introduce the white paper wash used in the typography reference. */
.reading-focus-layer > img,
.reading-focus-layer > .terrain-tiles {
  filter: none !important;
}

/* The homepage supplies measured HTML text-region bounds and its shot-led
   amount. Broad, irregular masks surround those reading zones, never the ball
   route. Their overlap uses alpha union, not two darkening photo filters.
   No timed reveal or perpetual animation is attached here. Setting amount to
   zero restores source colour, including in the reduced-motion presentation. */
@media (prefers-reduced-motion: reduce) {
  .reading-focus-layer { transition: none; animation: none; }
}