Link to posts after heading in a static page using query loop - guest authors

Yeah, that + is an Adjacent sibling combinator:

https://developer.mozilla.org/en-US/docs/Web/CSS/Adjacent_sibling_combinator

Its about one of the very few ( kinda ) logic operators with CSS.
More on combinators:

https://developer.mozilla.org/en-US/docs/Learn/CSS/Building_blocks/Selectors/Combinators

glad to hear thats working for you :)