#acceuil{
    background-image: url("sources/bt/accueil.png");
    height: 50px;
    width: 100px;
    background-repeat: no-repeat;
}
#acceuil:hover{
    background-image: url("sources/bt/accueil_surv.png");
}
#acceuil:active{
    background-image: url("sources/bt/accueil_appui.png");
}
#lesiles{
    background-image: url("sources/bt/lesiles.png");
    height: 50px;
    width: 100px;
    background-repeat: no-repeat;
}
#lesiles:hover{
    background-image: url("sources/bt/lesiles_surv.png");
}
#lesiles:active{
    background-image: url("sources/bt/lesiles_appui.png");
}
#cngetcip{
    background-image: url("sources/bt/CNGetCIP.png");
    height: 50px;
    width: 100px;
    background-repeat: no-repeat;
}
#cngetcip:hover{
    background-image: url("sources/bt/CNGetCIP_surv.png");
}
#cngetcip:active{
    background-image: url("sources/bt/CNGetCIP_appui.png");
}


#nature{
    background-image: url("sources/bt/nature.png");
    height: 50px;
    width: 100px;
    background-repeat: no-repeat;
}
#nature:hover{
    background-image: url("sources/bt/nature_surv.png");
}
#nature:active{
    background-image: url("sources/bt/nature_appui.png");
}

#historique{
    background-image: url("sources/bt/Historique.png");
    height: 50px;
    width: 100px;
    background-repeat: no-repeat;
}
#historique:hover{
    background-image: url("sources/bt/Historique_surv.png");
}
#historique:active{
    background-image: url("sources/bt/Historique_appui.png");
}

#contact{
    background-image: url("sources/bt/contact.png");
    height: 50px;
    width: 100px;
    background-repeat: no-repeat;
}

#contact:active{
    background-image: url("sources/bt/contact_appui.png");
}