body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #f0f0f0;
}

#sudoku-grid {
    display: grid;
    grid-template-columns: repeat(9, 50px);
    grid-gap: 2px;
    margin: 20px auto;
    width: 460px;
}

input {
    width: 48px;
    height: 48px;
    text-align: center;
    font-size: 18px;
    font-weight: bold;
}

input.system {
    background-color: #ddd;
    color: black;
}

input.correct {
    background-color: #e0ffe0;
    color: green;
}

input.wrong {
    background-color: #ffe0e0;
    color: red;
}

#timer {
    font-size: 20px;
    margin-top: 10px;
}


#sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 40px);
    gap: 2px;
    margin: 20px auto;
}

#sudoku-board input {
    width: 40px;
    height: 40px;
    text-align: center;
    font-size: 18px;
    border: 1px solid #ccc;
}

#sudoku-board input:disabled {
    background-color: #f0f0f0;
}