body {
    background: url('../img/tout_sur_la_gestion_dequipe.jpg') no-repeat center center fixed !important;
    -webkit-background-size: cover !important;
    -moz-background-size: cover !important;
    -o-background-size: cover !important;
    background-size: cover !important;
    margin: 0 !important;
    padding: 0 !important;
    min-height: 100vh !important;
}