How to remove divider line between post?

Hello! I am using the theme Twenty Fourteen. I have a child theme I’m making changes on. This is my site: https://www.sweeterreads.com/

I have been staring at code all afternoon trying to figure out how to remove the line divider that appears between posts where I don’t use a featured image. I only have 4 posts, but you’ll see how the line appears between my review of The Stand and my Winston Churchill quote, and then again between the quote post and The Alienist review.

Please, how can I make the line go away?

Thanks. ??