ng-custom-properties#binding-css-props.ts

@Component({
  selector: 'app-root',
  template: `
  <app-card [style]="style"></app-card>
  `,
})
export class AppComponent {
  get style() {
    return this.sanitizer.bypassSecurityTrustStyle(
      `--primary: lightblue; --accent: crimson`
    );
  }

  constructor(private sanitizer: DomSanitizer) {}
}