.sudoku-shell{color:#f8fafc;box-sizing:border-box;background:radial-gradient(circle at 50% 20%,#172554 0%,#0f172a 70%,#020617 100%);flex-direction:column;align-items:center;min-height:100vh;padding:1rem;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;display:flex;position:relative;overflow-x:hidden}.sudoku-header{z-index:10;border-bottom:1px solid #ffffff1a;justify-content:space-between;align-items:center;width:100%;max-width:600px;margin-bottom:1rem;padding:.75rem 1rem;display:flex}.sudoku-home{color:#60a5fa;background:#ffffff0d;border-radius:6px;padding:.4rem .8rem;font-size:.9rem;text-decoration:none;transition:all .2s}.sudoku-home:hover{color:#fff;background:#ffffff26}.sudoku-brand{align-items:center;gap:.75rem;display:flex}.sudoku-brand span.seal{color:#fff;background:linear-gradient(135deg,#3b82f6 0%,#1d4ed8 100%);border-radius:8px;justify-content:center;align-items:center;width:36px;height:36px;font-size:1.1rem;font-weight:900;display:inline-flex;box-shadow:0 4px 12px #3b82f64d}.sudoku-brand h1{margin:0;font-size:1.25rem;font-weight:700}.sudoku-brand small{color:#93c5fd;font-size:.65rem;display:block}.sudoku-stats-bar{box-sizing:border-box;background:#0f172acc;border:1px solid #ffffff1a;border-radius:12px;justify-content:space-between;align-items:center;width:100%;max-width:480px;margin-bottom:1rem;padding:.6rem 1.2rem;display:flex}.sudoku-board{-webkit-user-select:none;user-select:none;box-sizing:border-box;background:#0f172a;border:3px solid #64748b;border-radius:12px;grid-template-rows:repeat(9,1fr);grid-template-columns:repeat(9,1fr);width:90vw;max-width:460px;height:90vw;max-height:460px;display:grid;overflow:hidden;box-shadow:0 16px 36px #0009,inset 0 0 20px #0000004d}.sudoku-cell{-webkit-appearance:none;appearance:none;cursor:pointer;box-sizing:border-box;color:#38bdf8;background-color:#0000;border:1px solid #ffffff14;justify-content:center;align-items:center;padding:0;font-family:inherit;font-size:1.4rem;font-weight:700;transition:background .15s,box-shadow .15s,transform .1s;display:flex;position:relative}.sudoku-cell:focus-visible{outline-offset:-3px;z-index:3;outline:3px solid #fde047}.sudoku-cell.initial{color:#f8fafc;font-weight:900}.sudoku-cell.border-right-thick{border-right:2.5px solid #64748b!important}.sudoku-cell.border-bottom-thick{border-bottom:2.5px solid #64748b!important}.sudoku-cell.crosshair{background:#38bdf817}.sudoku-cell.selected{z-index:2;box-shadow:inset 0 0 0 2px #38bdf8,0 0 16px #38bdf880;background:#38bdf85c!important}.sudoku-cell.same-num{color:#fde047;box-shadow:inset 0 0 0 1.5px #facc15d9,0 0 10px #facc1559;background:#facc153d!important}.sudoku-cell.conflict{box-shadow:inset 0 0 0 1.5px #ef4444;color:#fca5a5!important;background:#ef444461!important}.cell-notes{color:#94a3b8;box-sizing:border-box;pointer-events:none;grid-template-rows:repeat(3,1fr);grid-template-columns:repeat(3,1fr);width:100%;height:100%;padding:1px;font-size:.62rem;font-weight:600;display:grid}.note-num{color:#cbd5e1;justify-content:center;align-items:center;line-height:1;display:flex}.sudoku-keypad{grid-template-columns:repeat(9,1fr);gap:6px;width:100%;max-width:460px;margin-top:1rem;display:grid}.keypad-btn{color:#fff;cursor:pointer;background:#ffffff14;border:1px solid #fff3;border-radius:8px;padding:.75rem 0;font-size:1.25rem;font-weight:800;transition:all .15s}.keypad-btn:active{background:#3b82f666;transform:scale(.95)}.sudoku-tools{gap:.75rem;margin-top:1rem;display:flex}.tool-btn{color:#e2e8f0;cursor:pointer;background:#ffffff14;border:1px solid #fff3;border-radius:8px;padding:.5rem 1rem;font-size:.9rem;font-weight:600;transition:all .2s}.tool-btn.active{color:#fff;background:#3b82f6;border-color:#60a5fa}