It's very small, but it's difficult to scan and painful to read. You could easily use built-in HTML structures to make it actually readable. Your site is, in my opinion, as much a deviation from the old readable web as the over-designed modern sites are.
There are lots[1] of small, "class-less" CSS libraries that would keep your site as small (or smaller, with tree-shaking in a modern build system) and it would end up much more user-friendly.