Jetpack background is different from the desktop site

Was told the best way to solve this was to enter the FTP file and do the following:
“locate the CSS file which can be found in this folder:
public_html/wp-content/plugins/jetpack/modules/minileven/theme/pub/minileven

I would recommend against editing plugin files, as your changes will then be overwritten next time you update the plugin. Instead, you’ll want to add that CSS into your Custom CSS editor under Appearance > Edit CSS in your dashboard.
There, you’ll also see the “Mobile compatible” option on the right, that will ensure that your custom CSS is added to the mobile theme as well.

Looking at your site on my mobile, it seems that the overall background is set to black already.

If you’d like the text background to be black as well, you’ll need to change the color of the text to white so things remain readable. Here is the code I would add to your custom CSS editor to make the mobile theme look similar to the desktop theme:

.mobile-theme #page,
.mobile-theme #branding,
.mobile-theme #colophon {
	background: #0a0a0a;
}

.mobile-theme #page #post-1 .entry-title {
	display: none;
}

.mobile-theme a,
.mobile-theme #site-generator a,
.mobile-theme .commentlist .edit-link a:before,
.mobile-theme .entry-meta .comments-link a:before,
.mobile-theme .entry-meta .edit-link a:before,
.mobile-theme a.comment-reply-link:before,
.entry-meta .edit-link a,
.commentlist .edit-link a,
.entry-meta .comments-link a,
a.comment-reply-link {
	color: #fff;
}

Thanks for your help Jeremy.

Worked a charm!

Don’t suppose you know how I can make the font size larger on my custom menu (for the desktop version)?

Don’t suppose you know how I can make the font size larger on my custom menu (for the desktop version)?

Something like his should do the trick:

.menu ul li a {
	font-size: 22px;
}

If you’re not familiar with CSS, I’d recommend this series of tutorials, it’s a good place to start:
https://dailypost.wordpress.com/2013/06/21/css-intro/

Thanks Jeremy that worked for me. Guide was useful too.

I’m now having a bit of trouble finding the right place in my css to increase the size of the “prev” and “next” navigation text links at the top of my page.

Any ideas?

My website: https://www.bitterberries.com/

Thank you

Something like this should do the trick:

.blognav a {
	font-size: 48px;
}

If you’re not familiar with CSS, I’d suggest checking this site to find out how you can use the right selectors to customize your site:
https://cssworkshop.wordpress.com/