app.component.html

<app-header />
<div class="app-container">
  <div class="app-body">
    <div *ngIf="loading" class="loader" aria-busy="true">
      <img class="loader-gif" src="/assets/gif/loader_circle_grey.gif" alt />
    </div>
    <ng-container *ngIf="!loading">
      <router-outlet name="left-pane"></router-outlet>
      <router-outlet></router-outlet>
    </ng-container>
    <router-outlet *ngIf="!loading" name="footer"></router-outlet>
  </div>
</div>
<router-outlet name="print"></router-outlet>