@media (max-width: 991px) {
  /* 3. Ebene (und tiefer) im mobilen Menü erst einmal eingeklappt */
  .ap-header .nav .dropdown-menu .dropdown-submenu > .dropdown-menu,
  .ap-header .nav .dropdown-menu .dropdown-submenu:hover > .dropdown-menu {
    display: none;
  }
  .ap-header .nav .dropdown-menu .dropdown-submenu.sub-open > .dropdown-menu {
    display: block;
  }

  /* Pfeil wie in der 1. Ebene, dreht sich beim Aufklappen */
  .ap-header .nav .dropdown-menu .dropdown-submenu > a {
    position: relative;
    padding-right: 40px;
  }
  .ap-header .nav .dropdown-menu .dropdown-submenu > a::after {
    content: "\f107";
    font-family: FontAwesome;
    font-size: 18px;
    line-height: 1;
    position: absolute;
    right: 21px;
    top: 50%;
    transform: translateY(-50%);
    transition: transform .2s;
  }
  .ap-header .nav .dropdown-menu .dropdown-submenu.sub-open > a::after {
    transform: translateY(-50%) rotate(180deg);
  }

  /* Hauptmenü-Punkte sofort zuklappen (Aufklappen bleibt animiert),
     sonst springt der Inhalt erst verzögert nach oben */
  .ap-header .nav > li:not(.open) > .dropdown-menu {
    transition: none;
  }
}