.navbar-nav > li:last-child > a {  
  background: url(../Images/hintergrund_culture-life.svg) center no-repeat !important;
  text-shadow: -1px 1px 0 #FFF,
          1px 1px 0 #FFF,
         1px -1px 0 #FFF;
        -1px -1px 0 #FFF;  
}