404 page does not apply the style for any arbitrary invalid URL

[jhlegarreta]

The 404 page seems to work correctly when introducing an invalid URL from the main page, e.g.
https://carpentries.github.io/lesson-example/random

However, the style is not correctly applied when introducing an invalid URL from any other page/episode or any other part of the URL, e.g.
https://carpentries.github.io/lesson-example/03-organization/index1.html
https://carpentries.github.io/lesson-example/03-organization1/index.html

[jhlegarreta]

I can confirm that applying the fix in #578 solved the issue in the repository where this was first detected:
https://github.com/carpentries-incubator/SDC-BIDS-dMRI

e.g.

and

Thanks for all the good wok.

Closing the issue.