*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

#board {
    display: grid;
    grid-template-columns: repeat(3, 80px);
    grid-template-rows: repeat(3, 80px);
    gap: 5px;
    margin: 20px auto;
    width: max-content;
}
.cell {
    width: 80px;
    height: 80px;
    border: 2px solid black;
    font-size: 2rem;
    text-align: center;
    line-height: 80px;
    cursor: pointer;
}