src/app/shared/forms/planet-rating-stars.component.html
<span class="stars" [ngClass]="{'stars-enabled':!disabled}">
<mat-icon
*ngFor="let i of [1,2,3,4,5]"
(mouseenter)="mouseOverStar(i)">star</mat-icon>
<!-- used simple arithmetic to get 20 and converted into % -->
<span [ngStyle]="{'width': starActiveWidth}">
<mat-icon
*ngFor="let i of [1,2,3,4,5]"
(mouseenter)="mouseOverStar(i)"
(mouseleave)="mouseOverStar(value)"
(click)="onStarClick(i)">star</mat-icon>
</span>
</span>