:root {
  --g-merge-sr: 1px;
  --g-merge-undo-h: var(--target);
}

#game-dom .mg-undo {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  min-height: var(--g-merge-undo-h);
  pointer-events: auto;
}

#game-dom .mg-undo:active {
  transform: translateX(-50%) scale(var(--press));
}

#game-dom .mg-sr {
  position: absolute;
  width: var(--g-merge-sr);
  height: var(--g-merge-sr);
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  pointer-events: none;
}