:root{--green:#16a34a;--grey:#6b7280;--black:#111418;--bg:#0b0d10;--fg:#e7e9ee;--muted:#9aa3af}*{box-sizing:border-box}body,html{margin:0;padding:0;background:var(--bg);color:var(--fg);font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif}.wrap{max-width:560px;margin:0 auto;padding:40px 20px 64px;text-align:center}h1{font-size:28px;letter-spacing:.04em;margin:0 0 4px}h1 .accent{color:var(--green)}.serial{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;letter-spacing:.18em;color:var(--muted);margin:0 0 28px}.err{color:#f87171}.hint{color:var(--muted);font-size:14px}.board-area{display:inline-flex;flex-direction:column;align-items:center;gap:16px}.board{position:relative;background:#1a1f26;border-radius:14px;padding:0}.tile{position:absolute;top:0;left:0;display:flex;align-items:center;justify-content:center;border-radius:10px;font-size:30px;font-weight:700;color:#fff;-webkit-user-select:none;-moz-user-select:none;user-select:none;box-shadow:inset 0 -3px 0 rgba(0,0,0,.25);transition:transform .32s cubic-bezier(.2,.8,.2,1)}.tile.green{background:var(--green)}.tile.grey{background:var(--grey)}.tile.black{background:var(--black)}.controls{display:flex;align-items:center;gap:14px}.status{color:var(--muted);font-feature-settings:"tnum";font-variant-numeric:tabular-nums}button{background:transparent;color:var(--fg);border:1px solid #2b323c;border-radius:8px;padding:8px 14px;cursor:pointer;font-size:14px}button:hover:not(:disabled){border-color:var(--green);color:var(--green)}button:disabled{opacity:.35;cursor:not-allowed}.controls .play{border-color:var(--green);color:var(--green);font-weight:600;min-width:92px}.status{margin-bottom:4px}.stats{list-style:none;padding:0;margin:32px auto 0;display:grid;grid-template-columns:1fr 1fr;grid-gap:12px;gap:12px;max-width:360px}.stats li{background:#141921;border:1px solid #232a33;border-radius:10px;padding:14px;display:flex;flex-direction:column;gap:6px}.stats span{font-size:12px;color:var(--muted)}.stats strong{font-size:18px}.panel{margin:32px auto 0;max-width:360px;background:#141921;border:1px solid #232a33;border-radius:12px;padding:20px;text-align:left}.panel h2{font-size:16px;margin:0 0 12px}.panel form{display:flex;flex-direction:column;gap:10px}.panel input{background:#0d1117;border:1px solid #2b323c;border-radius:8px;padding:10px 12px;color:var(--fg);font-size:15px}.panel input:focus{outline:none;border-color:var(--green)}.panel button{margin-top:4px}.panel .ok{color:var(--green);margin:0 0 10px}.panel .err{color:#f87171;margin:12px 0 0}