True, serving it to you was negligible, but that little extra being served millions of times, once for every request, in aggregate slows down servers, eats up peoples’ data, raises costs and generally quickens the heat death of the universe.

It's a KB of css, if that, probably much less. Cached, in a stylesheet request, not a style element. It's nothing. It amortized, not more data for every request. It's nothing.

The css doesn't need to be inlined in the page, so unless you disable caching it's not served for every request at all.