Rustdoc code view is broken

[RalfJung]

The source code view rendered by rustdoc, e.g. at https://doc.rust-lang.org/beta/src/std/error.rs.html, is broken:

If I scroll down a lot, the code shows up.

This happens with both Firefox Beta and Chromium, on Linux.

[bjorn3]

Same for me with firefox dev-edition, Linux.

[QuietMisdreavus]

It's a CSS issue that's fixed on nightly, which means we need to backport #56498 and/or related CSS PRs that happened around that time. cc @GuillaumeGomez

[GuillaumeGomez]

Just backporting the linked PR should be enough.

@QuietMisdreavus: I'll let you handle this part I guess. ;)

[QuietMisdreavus]

Since #56819 merged, and the linked page is no longer showing the issue, i'm closing this.