.navbar-brand img {
  width: 100% !important;
  height: auto !important;
  max-width: none !important;
  min-width: 100px !important;
}
/* Mobil */
@media (max-width: 768px) {
  .navbar-brand img {
    content: url('/sites/default/files/koehler_logo_mobil.png');
    width: 80px !important;
  }
}