If you want to use system fonts you should have a look at Lua(La)TeX (or Xe(La)TeX but I think focus shifted completely to the LuaTeX engine).
Luatex seems the more promising technology from the point of view of continued evolution of the Tex ecosystem, but there's been talk of Luatex being the successor to Pdftex for over ten years and it was held up by the fact that Luatex is not superconservative in the way it changes Tex layout and is less so than Xetex.
I've not really followed the discussion about succession to pdftex in Texlive in recent years, but it'd definitely be a change to their risk-averse ways if they did simply change 'latex' to mean 'lualatex'.
I can see they might be good sometimes but lots of them makes the page look busy.
And would you say that using lots of them is "minimalistic design"?
> I do like Tufte-style websites with sidenotes, but these don't show on mobile for this site, despite my tablet having a large screen.
Your iPad Safari reports having a width of ~1180 pixels in landscape mode, even though you have 2x the physical pixels (ie. 2x DPI scaling). This is much too small for sidenotes. Not getting sidenotes is correct. I don't think gwern.net is anything odd in this regard, every other responsive design website you visit must be giving you the same condensed view. Unless you're doing something like disabling scaling? Then in that case I guess maybe it should work and I'd need a screenshot & more information to see what's going wrong. (Maybe a media-query or something.)
> Gwern.net used Baskerville, but system Baskerville fonts don’t have small caps.
Can someone explain to me what is meant by this? I don't understand what not having small caps means. I use Baskerville in my LaTeX documents with Michael Spivak's MathTime2 Pro fonts I purchased. I am currently building my blog, and despite trying to just get it out there and worry about my ideal design later, I am considering trying Baskerville and other such fonts instead of sans-serif fonts.