src/app/common/router.animations.ts

import { trigger, state, animate, style, transition } from '@angular/animations';

export  function  slideInOpacity() {
    return  trigger('slideInOpacity', [
        state('void',  style({  opacity:  0 })),
        state('*',  style({  opacity:  1  })),
        transition(':enter', [
            style({ transform:  'scale(1)' }),
            animate(500)
        ])
    ]);
}