Handcrafted excerpt and read more button

I followed the approach in the article at the link below to get the read more button to show up when I have a handcrafted excerpt. I also like how the snippet allows for the text change in the customizer.

https://generatepress.com/forums/topic/read-more-button-for-handcrafted-excerpts/

However, I don't understand what CSS needs to be applied to have the read more text to appear like the read more button like a does naturally if there was NOT a hand-crafted excerpt.Thank you.