.board-yakazu {
  display: grid;
  gap: 0;
  width: min(92vw, 28rem);
  aspect-ratio: 1;
  border: 2px solid var(--board-line-strong, #3b2a1a);
}
.board-yakazu .cell {
  position: relative;
  display: grid;
  place-items: center;
  font-weight: 650;
  background: var(--board-cell, #fffaf0);
  border: 0;
  border-top: 1px solid var(--board-line);
  border-left: 1px solid var(--board-line);
}
.board-yakazu .cell.is-given { font-weight: 800; color: var(--board-given, #241a14); }
.board-yakazu .cell.is-black {
  background: #241a14;
  pointer-events: none;
}
.board-yakazu .cell.is-conflict { background-image: repeating-linear-gradient(-45deg, transparent, transparent 3px, rgba(180,40,40,.18) 3px, rgba(180,40,40,.18) 6px); }
#board.board-yakazu .cell.is-selected {
  background-color: var(--board-cell-sel);
  box-shadow: inset 0 0 0 2.5px var(--play-ring-active, #19D65A);
  border-radius: 5px;
  z-index: 2;
}