@media (min-width: 576px) and (max-width: 991.98px) {
    .header .navbar-nav {
        flex-direction: column !important;
    }
}

@media (max-width: 991.98px) {
    .dropdown-toggle::after, 
    .menu-toggle[role=button]::after {
        position: absolute;
        right: .5rem;
    }
}