.board{display:grid;grid-template-columns:repeat(8,1fr);width:min(640px,92vw);aspect-ratio:1;border-radius:14px;overflow:hidden;border:8px solid #161d29;box-shadow:0 24px 70px #0009;background:#111}.sq{position:relative;display:grid;place-items:center;aspect-ratio:1;user-select:none;cursor:pointer;transition:filter .12s}.sq:hover{filter:brightness(1.12)}.sq.light{background:#e6e1d5}.sq.dark{background:#71816f}.sq::after{content:attr(data-sq);position:absolute;left:5px;top:3px;font-size:9px;font-weight:700;color:#111;opacity:.22}.piece-img{width:82%;height:82%;object-fit:contain;display:block;pointer-events:none;user-select:none;filter:drop-shadow(0 7px 8px #0006);transition:transform .12s}.sq:hover .piece-img{transform:translateY(-2px)}.sq.sel{box-shadow:inset 0 0 0 5px #7c5cff}.sq.target:before{content:"";width:24%;height:24%;border-radius:50%;background:#20c997aa;box-shadow:0 0 0 5px #20c99733;position:absolute}.sq.target:has(.piece-img):before{width:82%;height:82%;background:transparent;border:5px solid #20c997aa;z-index:1}.sq.lastFrom,.sq.lastTo{box-shadow:inset 0 0 0 5px #f7c94899}