.dropdown-menu .dropdown-menu {
    position: relative!important;
    width: 100%;
}

.nav .open > a, .nav .open > a:hover, .nav .open > a:focus {
    background-color: #999999;
}

.open > .dropdown-menu {
    display: flex;
    flex-direction: column;
}
.dropdown-menu .dropdown-menu {
    background-color: #bebebe;
}

@media (min-width: 768px) {

    .dropdown .dropdown > a:after {
        content: "";
        display: inline-block;
        width: 0;
        height: 0;
        margin-left: 2px;
        vertical-align: middle;
        border-top: 4px solid;
        border-right: 4px solid transparent;
        border-left: 4px solid transparent;
    }

}



@media (max-width: 767px) {
    .dropdown-menu .dropdown-menu {
        display: flex;
        flex-direction: column;
        padding-left: 10px;
    }
}