next-ucap-messenger/projects/ucap-webmessenger-app/src/app/pages/messenger/components/main.page.component.html

<div class="container">
  <div class="left-side">
    <app-layout-messenger-left-side></app-layout-messenger-left-side>
  </div>
  <div class="contents">
    <app-layout-messenger-intro
      *ngIf="!(this.selectedChat$ | async)"
    ></app-layout-messenger-intro>
    <app-layout-messenger-messages
      *ngIf="!!(this.selectedChat$ | async)"
    ></app-layout-messenger-messages>
  </div>
  <div class="right-side">
    <app-layout-messenger-right-side></app-layout-messenger-right-side>
  </div>
</div>