Ubuntu 16.04 + Firefox 57, Ubuntu 16.04 + Chromium 62.0.3202.89, macOS Sierra + Firefox 57. Inaccessible to me on all - the font is too thin for me to read. I can't scale the font size up high enough either as the layout breaks. I used the `font-weight` hack initially, but after I clicked a couple of internal links that reset the override, I gave up.
Something like this should work with the font-weight override.