.jumbotron {
background: rgba(0, 0, 0, 0) url(/www/inscription_en_ligne_2.0/personnalisation/images/36453-Fond.jpg)no-repeat bottom left fixed;
/*background: rgba(0, 0, 0, 0) url(http://www.n7challenge.fr/assets/img/photos-perso-bg.jpg) no-repeat top center fixed;*/
/*background-position: left bottom;
background-repeat: no-repeat;
background-attachment: fixed;*/
background-size: cover;
}
.entete-bi h2, .entete-bi h3 {
    color: #fff;
}