I am trying to organize my app component for a new project and I have some issue with routing in Angular 8:

In general I have a landing page which is my first page. When I want to login in landing page I want to redirect user to /login without using main router outlet :
As you can see below:

```
    const routes: Routes = [
      { path: '', component: MainComponent },
      { path: 'signup', component: SignupComponent },
      { path: 'login', component: LoginComponent },
      { path: '**', component: PageNotFoundComponent },
     ]

```

And this is my AppComponent:

`<app-top-nav-bar></app-top-nav-bar>
 <router-outlet></router-outlet>
 <app-footer></app-footer>` 

Now I want to know, how can I add second router inside MainComponent. When I open the app, I want to see mainComponent with it's own module and router. I have second module and router. I want to modularize my app : see this <https://dzone.com/articles/howto-modularize-an-angular-application-by-example>