> couple of kb of CSS

Assuming an average line of CSS is 30 bytes, that's 66 lines of CSS. That definitely should be enough.

I would argue that if on a diet, 20 lines of CSS should be enough to provide a very readable, aesthetically inoffenseive website.

If browsers had consistent, sane defaults which were designed for readability, then CSS wouldn't even be necessary for most information sites. The symantics of HTML tags were observed uniformly, sane defaults could be assumed.