Could be a simple quick Fix !? Border – line and post page proglem

I’ve got a border line showing up in a place I don’t want it. Also, when viewing my posts, at the bottom appears a black box.

The border line is here https://www.relationship-oneness.com/site-overview/ You’ll see what I’m talking about. This was my first template page and after combing the CSS, I’m not sure what I’m doing wrong.

Second…. If you look here https://www.relationship-oneness.com/category/relationship-blogs/tiger-singleton-relationship-blog/

You’ll see the black box at the bottom. Any Idea on where this is coming from?

Thanks so much.