I really like simple drop-in CSS resets like the one I use for this site.

At the time of writing, I'm using Pico but I also considered tacit

The idea is that they provide nice default styling of HTML elements out of the box without the need to reference any specific classes.

The idea works well for sites that are much more content than layout - like this one.

Using tacit is a matter of incluing this link tag in the page's HEAD element:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.min.css">