.navbar .dropdown-menu {
    max-height: calc(100dvh - 160px);
    overflow-y: auto;
}
@media (max-width: 991.98px) {
    .navbar-collapse {
        max-height: calc(100dvh - 140px);
        overflow-y: auto;
        padding-bottom: 0.75rem;
    }
    .navbar .dropdown-menu {
        max-height: none;
        overflow: visible;
    }
}