.navbar .nav > li > a {
    color: #DF5E14;
    float: none;
    padding: 10px 15px;
    text-decoration: none;
    text-shadow: 0 0 0 #FFFFFF;
}

.nav navbar {
background-image: url(http://wp.luplarsundderleuchtturm.de/wp-content/uploads/2014/04/cropped-BALKEN_Flieger_2.jpg);
}