.echec {
    display: grid;
    grid-template-columns: repeat(9, auto);
    grid-template-rows: repeat (9, auto);
    width: fit-content;
    border: 4px solid #000000;
}

.echec div {
    width: 50px;
    height: 50px;
}

.echec div:nth-child(even) {
    background-color: black;
}