CSS-menu issue in angular project

import { MainPage } from './app.po';

describe('demo-project App', function() {
  let page: MainPage;

  beforeEach(() => {
    page = new MainPage();
  });

  it('Application should have a title', () => {
    page.navigateTo();
    expect(page.getTitle()).toEqual('Operator - Flight Operation Management');
  });

   it('Dashbaord should have a heading', function() {
    expect(page.getTitle()).toEqual('DASHBOARD');
  });
});

npm install @angular/{
    animations,
    common,
    compiler,
    compiler-cli,
    core,
    forms,
    http,
    platform-browser,
    platform-browser-dynamic,
    platform-server,
    router
}@4.0.0 typescript@latest --save

import { BrowserAnimationsModule } from @angular/platform-browser/animations

import { EVENT_MANAGER_PLUGINS } from '@angular/platform-browser';

@NgModule({
  providers: [
    {
      provide: EVENT_MANAGER_PLUGINS,
      useClass: PassiveEventsOptionPlugin,
      multi: true
    }
  ]
})
export class AppModule {}

@Injectable()
export class PassiveEventsOptionPlugin {
  private readonly passiveEvents = [
    'touchstart'
  ];

  constructor(@Inject(DOCUMENT) private doc: any) {}

  supports(eventName: string): boolean {
    return this.passiveEvents.some((event) => eventName.startsWith(event));
  }

  addEventListener(el: HTMLElement, event: string, listener: EventListener): () => void {
    // this is the important part. Adding the passive option
    const options = { passive: true };
    element.addEventListener(type, listener, options);

    return () => element.removeEventListener(type, listener, options);
  }

  addGlobalEventListener(
    element: GlobalEventTarget,
    eventName: string,
    listener: EventListener
  ): () => void {
    let target: EventTarget | undefined;

    if (element === 'window') {
      target = window;
    } else if (element === 'document') {
      target = this.doc;
    } else if (element === 'body' && this.doc) {
      target = this.doc.body;
    }

    return this.addEventListener(target as HTMLElement, eventName, listener);
  }
}