Hello,
you can use remote themes to style things in the app:
https://docs.moodle.org/dev/Moodle_Mobile_Themes
Another option would be to add Ionic1 classes to those buttons to make them look better (as long as they don't collide with your styles in web). E.g. Ionic has classes "row" and "col" to style tables.
Kind regards,
Dani