Low contrast when JS is disabled

[progval]

Problem

Here is https://rust-lang.github.io/mdBook/ with JS enabled:

and with JS disabled (or failed to load or whatever):

The second one has much lower contrast, making it harder to read

Steps

1. Disable JS
2. Go to https://rust-lang.github.io/mdBook/

Possible Solution(s)

Apply theme and/or colors using CSS only instead of JS

Notes

No response

Version

No response