[Theme: Simple Catch] Changing Font Style in Menu and Sidebar

For specific CSS queries, try CSS specific forums.

Looks like you have this CSS code in your custom CSS file:

li {
    color: #990000;
    font-style: italic;
}

That’s making all list items italic.

The best way to work with CSS is by using Firebug — which allows you to look at an element on a page and see exactly what CSS is affecting it.

Oh, and this is a good CSS resource:

https://www.w3schools.com/css/