freedesktop: unthemed specification pages

### Is there an existing issue outlining your problem?

- [x] I am using the latest version of the userstyle.
- [x] I have searched the existing issues and they do not solve my problem.

### What userstyles are you seeing the problem on?

lbl:freedesktop

### Describe your problem.

nav bar, header, dotted overlay fade, footer, codeboxes, text base, links, everything really.

### Attach screenshots.

### What browser(s) are you seeing the problem on?

Mozilla LibreWolf 147.0.3-1

### Any additional comments?

This issue happens on all specifications pages, tested on:
- https://specifications.freedesktop.org/desktop-entry/latest/index.html
- https://specifications.freedesktop.org/shared-mime-info/latest/ar01s02.html

Start with the lbl:freedesktop userstyle and compare the themed result against the reported specification pages for desktop-entry and shared-mime-info. Check the screenshots and inspect how the navigation, header, overlay fade, footer, codeboxes, text, and links are styled; done means these elements are themed consistently across all specification pages.

Written by the indexing model from the issue text.