body{
    text-align: center;
}

#jeu{
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    width: 300px;
    margin: auto; 

}

.case{
    border: 1px solid rgb(255, 0, 0);
    height: 100px;
    line-height: 100px;
    font-size: 60px;
}
p{
    margin: 60px;
}