.sudoku-container{text-align:center}.sudoku-grid{display:inline-block;margin:20px auto;border:2px solid #000}.sudoku-row{display:flex}.sudoku-cell{width:40px;height:40px;text-align:center;font-size:18px;border:1px solid #ccc;outline:none;color:#000}.sudoku-cell:disabled{background-color:#f0f0f0;color:#000;font-weight:700}.sudoku-cell:not(:disabled):focus{border:2px solid #00f;background-color:#e6f7ff}.sudoku-row:nth-child(3n) .sudoku-cell{border-bottom:2px solid #000}.sudoku-cell:nth-child(3n){border-right:2px solid #000}.sudoku-cell:focus{color:#000;outline:none}.sudoku-cell.error-cell{color:red;border-color:red}.sudoku-button{margin-top:20px;padding:10px 20px;font-size:1rem;font-weight:700;cursor:pointer;color:#fff;border:none;box-shadow:0 4px 6px rgba(0,0,0,.2);transition:background-color .3s;background-color:#494949;transform:scale(1.05)}.sudoku-button:hover{background-color:#6a6a6a}.sudoku-winMessage{margin-top:20px;font-size:1.2rem;font-weight:700;text-align:center;color:#4caf50;animation:fadeIn 1s ease-in-out}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}