body {
    display: flex;
    flex-direction: column;
}
nav {
    order: 1;
}
#menu_pas_a_pas{
    display: flex;
    justify-content: center;
    align-content: center;
    flex-wrap: wrap;
    list-style-type:none;
}
#menu_pas_a_pas li{
    padding: 1px 5px;
    margin: 3px 3px;
    border: 1px solid black; 
}
#menu_pas_a_pas li a{
    text-decoration: none;
}
iframe {
    order: 2;
    height: 3000px;
}
.clic {  
    background-color: #4a64fb;
    border-radius: 3px;
}
.clic a {
    color: rgb(255, 255, 255) !important;
}
/*********************** */
/**Contenu des Pas à Pas**/
/*********************** */