.main-header.navbar {
    background-color: #343a40;
}
.navbar-nav .nav-link {
    color: #fff !important;
    border-radius: 4px;
}

    .navbar-nav .nav-link.active {
        color: #fff !important;
        background-color: #007bff;
    }

.nav-treeview .nav-item{
    padding-left:2em;
}