body {
    --td-border: 3px;
}

#board {
    border-collapse: separate;
}

#board td {
    --cell-size: 52px;
    width: var(--cell-size);
    height: var(--cell-size);
    font-size: 28px;
    border: var(--td-border) solid var(--bs-body-color);
    text-align: center;
}

#board tr:nth-child(2n+1) td:nth-child(2n),
#board tr:nth-child(2n) td:nth-child(2n+1) {
    background-color: var(--bs-tertiary-color);
}

#game #board tr td.selecionado {
    background-color: var(--bs-info-bg-subtle);
    font-weight: bold;
}

#score {
    margin: 0 auto;
    text-align: center;
}

#score caption {
    font-weight: bold;
    text-align: center;
}

#game input[type="number"] {
    width: 5em;
}

@media (max-width: 400px) {
    #board td {
        --cell-size: 35px;
        font-size: 18px;
    }

    #game input[type="number"] {
        width: 3em;
    }
}