Getting rid of hideous buttons

Hi,

I need to get rid of the big black “continue reading” buttons on my site, which are unsightly. I just want it so only the headline clicks through to the full post.

Here is the site. It is running the Hemingway theme.
https://thenationalobservatory.com/

Last time I posted this, someone told me to go ask about it in the Hemingway forum. But nobody over there is answering! Any help would be appreciated.

-Nathan

PS Any advice on how to center the top menu would also be amazing!