:root{--bg:#31283d;--panel:#211a2b;--text:#f7f1fa;--muted:#a89caf;--accent:#f1b94d;--purple:#765f8f;--line:#756981}
*{box-sizing:border-box}body{margin:0;min-height:100vh;color:var(--text);font-family:Inter,"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg)}button{font:inherit}.sudoku-app{width:min(94vw,610px);margin:auto;padding:30px 0 48px}nav{display:flex;justify-content:space-between;margin-bottom:35px;color:#8f8397;font-size:12px}nav a{color:var(--text);text-decoration:none}nav a:hover{color:var(--accent)}
header{display:flex;align-items:end;justify-content:space-between;margin-bottom:22px}.eyebrow{margin:0 0 7px;color:var(--accent);font-size:11px;font-weight:800;letter-spacing:.18em}h1{margin:0;font:700 64px/1 Georgia,"Songti SC",serif;letter-spacing:0}.timer{text-align:right}.timer small{display:block;margin-bottom:4px;color:var(--muted);font-size:10px}.timer strong{font:700 21px Georgia,serif}
.settings{display:flex;gap:8px;margin-bottom:14px}.difficulty{flex:1;display:grid;grid-template-columns:repeat(3,1fr);padding:4px;border-radius:6px;background:#211a2b}.difficulty button{height:36px;border:0;border-radius:4px;color:var(--muted);background:transparent;cursor:pointer}.difficulty button.active{color:#211a2b;background:var(--accent);font-weight:800}.icon-btn,.new-btn{height:44px;border:0;border-radius:6px;color:var(--text);background:#4a3b5a;cursor:pointer}.icon-btn{width:44px;padding:0}.new-btn{padding:0 15px;color:#211a2b;background:var(--accent);font-weight:800}
.board-wrap{position:relative;width:100%;aspect-ratio:1}.sudoku-board{height:100%;display:grid;grid-template-columns:repeat(9,1fr);border:3px solid #17121d;background:#17121d}.cell{position:relative;display:grid;place-items:center;min-width:0;border:0;border-right:1px solid var(--line);border-bottom:1px solid var(--line);color:#f0c365;background:#faf7fb;font:700 clamp(21px,6vw,33px) Georgia,serif;cursor:pointer}.cell:nth-child(9n){border-right:0}.cell:nth-child(n+73){border-bottom:0}.cell:nth-child(3n):not(:nth-child(9n)){border-right:3px solid #332a3e}.cell:nth-child(n+19):nth-child(-n+27),.cell:nth-child(n+46):nth-child(-n+54){border-bottom:3px solid #332a3e}.cell.given{color:#30283a;background:#eee7f1}.cell.related{background:#e1d7e7}.cell.same{background:#d2c1de}.cell.selected{background:#c4aed4;box-shadow:inset 0 0 0 3px var(--accent)}.cell.error{color:#d94343;background:#f5d4dc}.notes{position:absolute;inset:3px;display:grid;grid-template-columns:repeat(3,1fr);align-items:center;color:#786b80;font:600 10px Arial}.notes i{text-align:center;font-style:normal}.pause-layer{position:absolute;inset:0;display:none;place-items:center;align-content:center;gap:18px;background:#211a2bf2}.pause-layer.show{display:grid}.pause-layer strong{font:700 34px Georgia,serif}.pause-layer button{height:44px;padding:0 24px;border:0;border-radius:5px;color:#211a2b;background:var(--accent);font-weight:800;cursor:pointer}
.number-pad{display:grid;grid-template-columns:repeat(9,1fr);gap:6px;margin-top:16px}.number-pad button{aspect-ratio:1;border:0;border-radius:5px;color:var(--text);background:#4a3b5a;font:700 22px Georgia,serif;cursor:pointer}.number-pad button:hover{background:#604e72}.number-pad button.used{opacity:.3}.tools{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:11px}.tools button{height:52px;border:1px solid #5b4c69;border-radius:6px;color:var(--text);background:transparent;cursor:pointer}.tools span{margin-right:5px;color:var(--accent);font-size:18px}.tools i{padding:2px 5px;border-radius:3px;color:#211a2b;background:var(--accent);font-size:10px;font-style:normal}.tools button.active{background:#4a3b5a}.message{height:18px;margin:15px 0 0;text-align:center;color:var(--muted);font-size:12px}
.result{position:fixed;inset:0;display:none;place-items:center;padding:20px;text-align:center;background:#17121de8;backdrop-filter:blur(8px)}.result.show{display:grid}.result>div{width:min(90vw,380px);padding:38px;border:1px solid #5b4c69;border-radius:8px;background:#31283d}.result h2{margin:5px 0 10px;font:700 32px Georgia,"Songti SC",serif}.result>div>p:not(.eyebrow){margin:0 0 23px;color:var(--muted)}.result button,.result a{display:block;width:100%;height:45px;margin-top:8px;border:0;border-radius:5px;text-decoration:none;line-height:45px;cursor:pointer}.result button{color:#211a2b;background:var(--accent);font-weight:800}.result a{color:var(--text);background:#4a3b5a;font-size:13px}
@media(max-width:560px){.sudoku-app{padding-top:21px}nav{margin-bottom:24px}h1{font-size:52px}.settings{flex-wrap:wrap}.difficulty{flex-basis:100%;order:2}.new-btn{flex:1}.cell{font-size:22px}.notes{font-size:8px}.number-pad{gap:4px}.number-pad button{font-size:19px}.tools button{height:48px;font-size:12px}}