:root{font-family:system-ui,sans-serif;color:#29251f;background:#f5f1e8}*{box-sizing:border-box}body{margin:0}main{width:min(94vw,680px);margin:32px auto;text-align:center}h1{margin:0 0 14px}.info{display:flex;justify-content:space-between;margin-bottom:12px}.board{display:grid;grid-template-columns:repeat(15,1fr);aspect-ratio:1;padding:14px;background:#d7a557;border:2px solid #6e4c20}.point{position:relative;min-width:0;padding:0;border:0;background:linear-gradient(#594522,#594522) center / 100% 1px no-repeat,linear-gradient(90deg,#594522,#594522) center / 1px 100% no-repeat;cursor:pointer}.point:focus-visible{outline:3px solid #2767c5;z-index:1}.stone{position:absolute;inset:8%;z-index:1;border-radius:50%;box-shadow:0 2px 4px #0006}.black{background:#171717}.white{background:#f8f8f4;border:1px solid #aaa}.notice{min-height:1.5em;color:#a3261d}@media(max-width:520px){main{margin-top:18px}.info{align-items:center;flex-direction:column;gap:4px}.board{padding:8px}}