Angular 6 change library style in project

change-library-style.md

Change Style from Angular Library

If we create a library for reusable components with Angular 6, and you'll find that it's not possible to update the styles from the library. One way to do that is put ':host ::ng-deep':

// from library
.example-class {
   font-weight: bold;
}

// in app
:host ::ng-deep .example-class {
  font-weight: normal;
}