.sudoku-container{display:flex;flex-direction:column;align-items:center}.sudoku-grid{border-collapse:collapse}.sudoku-grid td{border:1px solid #888;width:40px;height:40px;padding:0}.sudoku-grid input{width:100%;height:100%;text-align:center;font-size:1.2em;border:none;outline:none}.block-border-right{border-right:2px solid #222!important}.block-border-bottom{border-bottom:2px solid #222!important}.user-cell input{color:#000!important}.solved-cell input{color:#22c55e!important}.button-row{display:flex;gap:12px;margin-top:16px}button{margin-top:0}body{background:linear-gradient(120deg,#f8fafc,#e0e7ff);font-family:Segoe UI,Roboto,Arial,sans-serif;margin:0;min-height:100vh;color:#222}main{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh}h2{font-size:2.2rem;font-weight:700;color:#6366f1;margin-bottom:1.5rem;letter-spacing:1px}.sudoku-container{background:#fff;border-radius:18px;box-shadow:0 4px 32px #6366f11f,0 1.5px 6px #6366f114;padding:2.5rem 2rem 2rem;margin-top:2rem;transition:box-shadow .5s}.sudoku-container:hover{box-shadow:0 8px 48px #6366f12e,0 2px 8px #6366f11f}.sudoku-grid{border-collapse:collapse;margin-bottom:1.5rem}.sudoku-grid td{border:1px solid #cbd5e1;width:44px;height:44px;padding:0;background:#f1f5f9;transition:background .5s}.sudoku-grid input{width:100%;height:100%;text-align:center;font-size:1.3em;border:none;outline:none;background:transparent;color:#6366f1;font-weight:600;transition:background .5s,color .5s}.sudoku-grid input:focus{background:#e0e7ff;color:#1e293b}.block-border{border-right:2.5px solid #6366f1!important;border-bottom:2.5px solid #6366f1!important}button{background:linear-gradient(90deg,#6366f1,#818cf8);color:#fff;border:none;border-radius:8px;padding:.7rem 1.5rem;font-size:1rem;font-weight:600;cursor:pointer;box-shadow:0 2px 8px #6366f114;transition:background .5s,box-shadow .5s}button:hover{background:linear-gradient(90deg,#818cf8,#6366f1);box-shadow:0 4px 16px #6366f129}