Where to change font size on drop down menu?

I’m using SAB version 12.4 on Wasta Linux 24.04. I have two book collections which are using different scripts Tibetan and Latin they are reflecting the same language but using different scripts for the benefit of the reader. Originally I started off with Tibetan Script but I knew that only 30% of the population can read it fluently which made me think of having 2 scripts so now I’m about to publish our app with an major update where people can use phonetic Tibetan font or phonetic Latin font to read the Scriptures in the vernacular

So when I look at the drop down menu of the Latin Book collection to select the Scripture books (eg: Genesis, Exodus etc) the font size is quite large. How can I reduce the font size?

Do I only go to the Book collection for the Latin script and click on styles or do I do it from some other location in SAB?

If this is the correct location which style do I change?

What is it’s name?