Problems with basic things to render

Ionic Framework
1

Hello guys, I have basic problems with rendering UI components from docs. I tried to render for example basic ion-item with avatar and details.

<ion-item>
  <ion-avatar slot="start">
    <img [src]="avatar" />
  </ion-avatar>
  <ion-label>
    <h3>{{name}}</h3>
    <h3>{{address}}</h3>
    <p>{{numberId}}</p>
  </ion-label>
</ion-item>

And the problem is that styles aren’t good like it should be. I don’t know if i am missing something, or configuration is bad in ionic project or something else. Please help