Website name and menu items are underlined on hover

I’m using the shapely child theme that was provided in the forums. I didn’t modify the CSS for the menu/top nav items, but when I hover over them, they’re underlined instead of just changing color. Can you help me restore the original CSS?

On a related note, I noticed the font of the child theme (such as for header and body text) is different from the parent theme. It’s not a big deal, but I’m not sure why it changed or how to change it back.