body {
    margin: 0;
    background-color: blue;
    display: flex;
    justify-content: center;
}

#tabuleiro {
    width: 500px;
    height: 500px;
    background-color: rgb(0, 207, 214);
    margin-top: 200px;
    border-radius: 20px;
}

#linha1, #linha2, #linha3 {
    width: 100%;
    height: 33%;
    display: flex;
}

.casas {
    width: 33%;
    height: 100%;
    text-align: center;
    font-size: 120px;
}