:root{--board: min(94vmin, 50vh);--cell: calc(var(--board) / 9);--bg: #fdfcf9;--ink: #16181d;--user: #12509c;--line: #b7bcc6;--box: #1b1e24;--sel: #ffe08a;--peer: #eef4fb;--same: #d8ead9;--wrong-bg: #ffd9a8;--wrong-ink: #a63c00;--conflict: #d84315;--primary: #1565c0;--btn-bg: #ffffff;--btn-ink: #16181d;--btn-line: #9aa2b1}*{box-sizing:border-box}html,body{margin:0;padding:0;background:var(--bg);color:var(--ink);font-family:PingFang SC,Hiragino Sans GB,Microsoft YaHei,Noto Sans CJK SC,system-ui,sans-serif;-webkit-text-size-adjust:100%;overflow-x:hidden}body{min-height:100dvh}button{-webkit-tap-highlight-color:transparent;touch-action:manipulation;cursor:pointer;font-family:inherit}.app{max-width:560px;margin:0 auto;height:100dvh;overflow:hidden;padding:6px 10px calc(6px + env(safe-area-inset-bottom));display:flex;flex-direction:column;align-items:center;gap:6px}.header{width:var(--board);display:flex;align-items:center;justify-content:space-between;gap:8px}.title{margin:0;font-size:5.4vmin;font-weight:800;letter-spacing:.02em;color:#9a5b00;white-space:nowrap}.head-btns{display:flex;gap:8px}.head-btn{font-size:4vmin;padding:8px 14px;min-height:46px;white-space:nowrap}.guide{margin:0;width:var(--board);text-align:center;font-size:4vmin;color:#55606f}.guide.pulse{animation:guide-pulse .9s ease}@keyframes guide-pulse{0%,to{color:#55606f;transform:scale(1)}30%{color:#b5471f;transform:scale(1.05)}}.board-wrap{position:relative;width:var(--board)}.board-slop{position:absolute;inset:-6px;touch-action:manipulation}.board{position:relative;width:var(--board);height:var(--board);display:grid;grid-template-columns:repeat(9,1fr);grid-template-rows:repeat(9,1fr);border:4px solid var(--box);border-radius:6px;background:#fff;overflow:hidden}.cell{border:none;border-right:1.5px solid var(--line);border-bottom:1.5px solid var(--line);background:#fff;color:var(--ink);font-size:calc(var(--cell) * .62);font-weight:600;line-height:1;padding:0;display:flex;align-items:center;justify-content:center;-webkit-user-select:none;user-select:none}.cell.edge-r{border-right:none}.cell.edge-b{border-bottom:none}.cell.thick-r{border-right:4px solid var(--box)}.cell.thick-b{border-bottom:4px solid var(--box)}.cell.given{color:var(--ink);font-weight:800;background:#f0f1f4}.cell.user{color:var(--user);font-weight:700}.cell.peer{background:var(--peer)}.cell.same{background:var(--same)}.cell.selected{background:var(--sel);box-shadow:inset 0 0 0 4px #f2a900}.cell.wrong{background:var(--wrong-bg);color:var(--wrong-ink);font-weight:800}.cell.conflict{box-shadow:inset 0 0 0 5px var(--conflict);font-weight:800}.cell.selected.wrong,.cell.selected.conflict{box-shadow:inset 0 0 0 4px #f2a900,inset 0 0 0 9px var(--conflict)}.btn{border:2px solid var(--btn-line);border-radius:14px;background:var(--btn-bg);color:var(--btn-ink);font-weight:700;line-height:1}.btn:active{transform:translateY(1px);filter:brightness(.96)}.btn.primary{background:var(--primary);border-color:var(--primary);color:#fff}.btn.ghost{background:#fff;border-color:var(--btn-line);color:#55606f}.pad{width:var(--board);display:grid;grid-template-columns:repeat(3,1fr);gap:7px}.num{min-height:max(46px,7.6vh);font-size:6vmin;font-weight:800}.actions{width:var(--board);display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:7px}.action{min-height:max(46px,6.8vh);font-size:4.4vmin}.action.erase{background:#fff3e0;border-color:#e8935a;color:#b5471f;font-weight:800}.overlay{position:fixed;inset:0;background:#14181e8c;display:flex;align-items:center;justify-content:center;padding:20px;z-index:10}.overlay.hidden{display:none}.card{background:#fff;border-radius:22px;padding:26px 22px 24px;width:100%;max-width:460px;box-shadow:0 12px 40px #0000004d;text-align:center}.big-btn{width:100%;min-height:72px;font-size:6vmin;margin-top:18px}.win-card{border:4px solid #f0b429;background:linear-gradient(165deg,#fff,#fff6e0);position:relative;overflow:hidden;animation:win-pop .42s cubic-bezier(.18,.9,.3,1.3)}@keyframes win-pop{0%{transform:scale(.82);opacity:0}to{transform:scale(1);opacity:1}}.win-burst{font-size:20vmin;line-height:1.1;margin-bottom:4px;animation:win-burst .75s ease .08s both}@keyframes win-burst{0%{transform:scale(0) rotate(-18deg)}60%{transform:scale(1.25) rotate(10deg)}to{transform:scale(1) rotate(0)}}.win-big{font-size:8.5vmin;font-weight:900;color:#b23c00;line-height:1.25}.win-sub{margin-top:10px;font-size:5.2vmin;color:#4a4a4a}.win-btns{margin-top:18px;display:flex;flex-direction:column;gap:12px}.win-btns .big-btn{margin-top:0}.help-card{text-align:left}.help-title{margin:0 0 14px;text-align:center;font-size:7vmin;font-weight:900}.help-list{margin:0;padding-left:1.1em;font-size:4.8vmin;line-height:1.7;color:#1d2129}.help-list li{margin-bottom:12px}@media (max-height: 640px){:root{--board: min(90vmin, 42vh)}.num{min-height:max(40px,6.8vh);font-size:5vmin}.action{min-height:max(40px,6vh)}}