"Archives" widget not showing up properly

Hello,

Any help is greatly appreciated!

I’m just building my website using the Ellipsis theme and I’m having 2 problems, both with the blog portion of the site.

1) The Archives and Categories widgets showing up properly against the background. Instead of being highlighted in a box like the other widgets, they’re just blending in. I’m pretty good at learning things quickly, but I’m new to WordPress, so please give me step by steps (sorry!).

2) I can’t find where to change the background color just for the blog portion of the site itself. I’ve used the Google Chrome Developer’s Tool but it didn’t tell me where to look for the element. And the element had a line through it, so when I tried to change it within DevTools, it didn’t change it – it just gave me a little yellow triangle with an exclamation point next to the element. I looked in the Style.css, but it says to look in library/less. I looked there but there was nothing to do with the page background, only the comments background.

Here’s the area of my site I’m talking about: https://www.amberwingart.com/classic-blog/