table.bitboard {
    margin-left: auto;
    margin-right: auto;
    font-family: Courier New, monospace;
    padding: 0.3em;
    border: 2px solid black;
    border-collapse: collapse;
    border-spacing: 0px;
    margin-left: 0px;
    margin-right: auto;
}

table.bitboard td {
    border: 1px dashed black;
    width: 2em;
    height: 2em;
    text-align: center;
    font-weight: bold;
}

table.bitboard td.mask {
    background: lightsteelblue;
}

table.bitboard td.maskw {
    background: lightsteelblue;
    color: white;
}