Modify CSS for Ionic4 Components

I’m converting an Ionic-v3 to v4. General question with the new components, can we modify the generic css for any component. I believe the answer is no and we can only modify the variables that have been exposed.

So - the only way to change the css of a component is to clone it and modify it in the component definition?

Specifically, I’m trying to modify the width and it seems to be fixed length (using position=“fixed”).