#grille {
    width: 30vmin;
    height: 30vmin;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
}

#grille .case {
    border: solid black 1px;
    display: grid;
    place-items: center;
}

body{
    background-color: rgb(242, 242, 242);
}
h1{
    font-family: Arial, Helvetica, sans-serif;
    font-size: 60px;
    text-align: center;
    color: rgb(255, 145, 0);
}