#gameBoard {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    grid-template-rows: repeat(3, 100px);
    grid-gap: 10px;
    margin: 0 auto;
}

.cell {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #ddd;
    font-size: 36px;
    cursor: pointer;
}

#restartButton {
    display: block;
    margin: 20px auto;
}