Dark theme is very low contrast when JS is not loaded

[progval]

Without JS:

With JS:

(layout is actually the same, it's just a side-effect of me changing the viewport size between both shots)

[tulir]

Those are two different themes (there are 2 light and 3 dark options). Anyway, probably a mdbook issue

[progval]

submitted to rust-lang/mdBook#2041