*{box-sizing:border-box}body{margin:0;background:#edf3f2;color:#193b3d;font-family:system-ui,'Malgun Gothic',sans-serif}main{max-width:620px;margin:auto;padding:clamp(20px,5vw,36px)}header a{display:inline-block;min-height:44px;color:#145cc8;font-weight:700}h1{font-size:clamp(27px,6vw,38px);letter-spacing:-.04em;margin:8px 0}p{line-height:1.6;margin:0}.settings{display:flex;gap:12px;flex-wrap:wrap;margin:22px 0 8px}.settings-help{font-size:14px;margin-bottom:12px}label{display:grid;gap:6px;font-weight:700}select,button{font:inherit;color:#193b3d;border:1px solid #a2bbb3;background:white;border-radius:10px;min-height:48px;padding:10px 14px}button{cursor:pointer;font-weight:700}button:disabled{opacity:.52;cursor:default}button:focus-visible,select:focus-visible,a:focus-visible{outline:4px solid #145cc8;outline-offset:3px}.status{min-height:3em;font-weight:700}.board{min-height:180px;display:flex;flex-wrap:wrap;justify-content:center;align-content:center;gap:10px;padding:25px;border-radius:22px;background:#dcebe2;border:2px solid #b5d1c1}.stone{display:block;width:52px;height:43px;border:2px solid #416d60;border-radius:48% 56% 45% 55%;background:radial-gradient(circle at 33% 27%,#f0f9ef 0 13%,#a9cfb7 16% 62%,#719e87 100%);box-shadow:0 3px 0 #6e9181;animation:appear .2s ease-out}@keyframes appear{from{transform:scale(.92)}to{transform:scale(1)}}.choices,.controls{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px}.choices button{flex:1;background:#145cc8;color:white;border-color:#145cc8}.controls button{flex:1}.result{margin-top:18px;border-left:5px solid #175c43;border-radius:6px;background:#e4f2e9;padding:16px}.result strong{display:block;margin-bottom:8px}[hidden]{display:none!important}.board.dense{gap:8px}.board.dense .stone{width:40px;height:33px}.practice{margin-top:10px}.practice summary{min-height:48px;display:flex;align-items:center;cursor:pointer;font-weight:700}@media(prefers-reduced-motion:reduce){.stone{animation:none}}