How to style jacket page created during conversion

[tgiladi]

I was using the polish feature to insert a jacket page into my epubs, and after getting some help from other users in these forums, managed to get my jacket looking just how I like, by customizing the template file for the jacket.

But after realizing that something in my polish settings must be the cause for my not being able to upload to google play books, I'd decided to convert my books (epub to epub) and use the insert metadata option instead.

This works well and google play books accepts the books with no issue. However, the formatting for the jacket page itself is different than how it was when I was polishing. I noticed that the style is coming from the stylesheet.css file and I can make some adjustments there when editing the book after conversion to fix what I need. But this file is different than the stylesheet.css file I have in my resources folder, next to my template file.
Another difference I noticed is that in the body of the html code for the jacket, I have some <p> tags added for some reason, which also affect how the end result looks like.

How can I customize the jacket file created by conversion similarly to how I managed that for the jacket created during conversion?

[kovidgoyal]

The customisation is the same, but conversion processes all contents of a book including the jacket, which is why you will see differences.