body{
    background-color: greenyellow;
    margin: 0px;
    padding: 0%;
}
nav{
    background-color: white;
    padding: 20px;
    display: flex;
    flex-direction: row;
    justify-content: center;
    margin-bottom: 20px;
}
#but_gen{
    display: flex;
    flex-direction: row;
    margin: 0 50px;
}
.colonne{
    display: flex;
    flex-direction: column;
}
.ligne{
    display: flex;
    flex-direction: row;
    justify-content: center;
    
}
.salle{
    height: 150px;
    width: 150px;
    border: solid black 3px;
    display: flex;
    justify-content: center;
    align-items: center;
}