Tried other resolutions to change background color but still can't

I’m using the theme Zero Gravity, and have created a child theme. They have a customizable background color option, but changing the color there doesn’t have any effect on my site. It stays white, and I’d like to change it to a light gray.

Based on other suggestions, here’s what I’ve put into my custom CSS:

body {
	background-color: #F2F0F0;
	color: #000000;
}

I found another site that recommended something similar, but using “.site-content” instead of “body”. This DID have an effect, but only colored grey behind whatever text I had in the body, rather than the whole background of the page.

I’ve seen someone recommend just “background” rather than “background-color.” I know there’s got to be a right way to do this for my theme.

Here’s the link to my site:
https://www.oace.info/

I would greatly appreciate any suggestions or advice before I pull my hair out and change my theme again.

Thank you so much expert coders!!!