IONIC4 : how to use cssClass for Loading , it is doesn't work

Question

I want to change ion-loading style using cssClass ,my code as follow:

loading.page.ts :

@Component({
    selector: \'app-loading\',
    templateUrl:          


        

Answer 1

theme/variables.scss

ion-loading.custom-loading {
  .loading-wrapper {
    background: transparent;
    box-shadow: none;
  }
}

I don't know why, but it works in Ionic4.

If you write in loading.page.scss, it doesn't work.