.navbar-default .nav .dropdown-menu {
    margin-top:50px !important;
    width: 270px !important;
}

.container-fluid {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: #8C8C8C; 
}

/* Make dropdown menu background and text white */
.dropdown-menu {
    background: rgba(140,140,140,1) !important;
}

#main_navigation ul.dropdown-menu {
    background-color: rgba(140,140,140,1) !important;
}

.dropdown-menu li > button {
    color: #fff !important;
}

#main_navigation .dropdown-menu {
    background-color:unset !important;
}