.stone-builder{display:flex;align-items:center;justify-content:center;gap:24px;width:100%;max-width:850px;margin:auto}
.stone-reserve{flex:0 0 160px;padding:16px;background:#fffaf0;border:1px solid #decdae;border-radius:18px;align-self:center}
.stone-reserve strong{display:block;text-align:center;font-size:15px;margin-bottom:12px;color:#625c72}
#reserveStones{position:relative;height:160px}
#reserveStones span{position:absolute;transform:translate(-50%,-50%);width:18px;height:18px;border-radius:50%;background:#8875ba;box-shadow:inset 2px 2px 3px #b9aed9,0 2px 2px #64518035}
#stoneGrid{display:block;flex:1;min-width:0;width:100%;max-width:480px;max-height:480px;touch-action:none;user-select:none}
.stone-cell{cursor:pointer}.stone-cell rect{fill:#fffdf8;stroke:#b4cdd3;stroke-width:1}.stone-cell circle{fill:#8875ba;stroke:#b9aed9;stroke-width:2;opacity:0;pointer-events:none}.stone-cell.filled circle{opacity:1}.stone-cell:focus-visible{outline:none}.stone-cell:focus-visible rect{stroke:#735aa8;stroke-width:3}
#squareOutline rect{fill:none;stroke:#438860;stroke-width:3}#squareOutline text{font:900 23px Nunito,sans-serif;fill:#28784b}
#squareEquation{min-height:30px;margin:0;text-align:center;color:#28784b;font:900 23px Nunito,sans-serif}
#gameShell.is-fullscreen .stone-builder{flex:1;min-height:0}
#gameShell.is-fullscreen #stoneGrid{height:100%;max-height:100%;max-width:none;min-height:0}
@media(max-width:620px){.stone-builder{flex-direction:column;gap:4px}.stone-reserve{flex:none;width:100%;max-width:360px;padding:8px 12px}.stone-reserve strong{margin:0 0 6px}#reserveStones{height:100px;max-width:280px;margin:auto}#reserveStones span{height:14px;width:14px}#stoneGrid{flex:auto}#gameShell.is-fullscreen #stoneGrid{flex:1;height:0}}