Page title changed into small/normal size inside viewing mode

The template that I’ve used is called Aurora by Benny Guo found within the template settings. I really loved this template and have used several css snippets to suit my preference for appearance. However, in viewing mode, the page title changed its size into normal text size. I want it to be at least bigger than the normal size. Do you have any css snippets to help me fix this? P/S I’m new at reading codes.

Things I have tried

I have searched for the codes that are changing the size of my page title inside viewing mode and failed.

What I’m trying to do

Wanting to remain the size of the page title inside viewing mode, if not bigger than the normal text size.