body {
    font-size: 12px;
}

#board {
    margin-left: auto;
    margin-right: auto;
}

#board tr td {
    border: 0.125rem solid white;
    background: #f1f1f1;
    width: 1.5rem;
    height: 1.25rem;
    text-align: center;
    cursor: pointer;
}

#board tr td.revealed {
    background: #cccccc;
}

#board tr td.mine {
    background: red;
}

#board tr td.flagged {
    background: blue;
}