I've read that my note system Wikidpad, which exports to very simple HTML, can use CSS (http://wikidpad.sourceforge.net/help/HtmlCss.html) The elements in the output are not more than basic headings, bullet points and tables.

I'd like to try some kind of improved style, but I as I have no knowledge about CSS, so the best I can do is to save some Myfile.css to a directory :) However if I google "CSS template" I get all sorts of complicating results that I cannot make sense of :( Am I using wrong terminology?

Can you suggest what I should search for or maybe you even know a ressource where a get a simple CSS file with some decent standard HTML elements. I do not wish to make custom adjustments.