Is it not computing to 16px for your screen? I feel like you must have problems on 99% of websites if 16px font does not render large enough for you to read. Heck, HackerNews renders at 10.6/12px for me.
Ah, the page has a setting for displaysize. It was set to 0.5x when I ooened the link. Most pages work just fine if someone does not fiddle with stuff ;)
Just off-black on a slightly creamy white.
May even stick with #000 for text.
Giving users ability to select a white, off-white, inverse, or solarised scheme is also useful.
See also https://contrastrebellion.com