Ionic 4 + Angular 7: How to print a page

Greetings,
I have to implement a mechanism to print a page or a section in it in Ionic 4.
On Ionic 3 I used the mechanism as explained in:

I was unable to implement it on Ionic 4. Mostly because I couldn’t find the main.css file (on Ionic-3 it was placed in build directory.

Any idea?