/*plus petit que 1024*/
@media only screen
and (max-width : 1024px){
    #col_principal{
        width:auto;
        float:none;
    }
}

/* plus petit que 768*/
@media only screen
and (max-width : 768px) {
    #header .colonne{
        flex-direction: column;
        align-items: center;
    }
    
    #section_footer_1 .colonne{
        width: 100%;
        text-align: center;
    }
    
    #section_footer_2{
        flex-direction: column;
        align-items: center;
    }
    
    #footer #menu-header-1,
    #header #menu-header{
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media only screen
and (max-width : 320px) {
   
}