Epubs do not use system scrollbars.

[JamesR98]

Scrollbars now look like this regardless of theme:

As I understand this is due to atril acting as a wrapper to libwebkit2gtk, as such I know fixing this issue is rather complicated.

[lukefromdc]

Any chance this started with an update to libwebkit2gtk?

[JamesR98]

Any chance this started with an update to libwebkit2gtk?

Yeah sorry I should've investigated this more before posting.

The issue is somewhere between 2.44 and 2.46 of libwebkit2gtk-4.1:
https://www.mail-archive.com/webkit-gtk@lists.webkit.org/msg03954.html

The a reply in the mailing list states that evolution and geary have the same problem but so far as I can tell neither have solved it.

Those on debian can downgrade by installing 2.44 here:
https://snapshot.debian.org/package/webkit2gtk/

Specifically one needs the packages:
libjavascriptcoregtk-4.1-0_2.44*
libwebkit2gtk-4.1-0_2.44*

After this the scrollbars return, as an aside in yelp it seems to read some gtk theme values to control the background color and text color, that would be pretty cool for atril to support.

if webkit2gtk is just reading an html file using the webkit engine and since webkit supports css scrollbars it should be possible to inject a css file with the scrollbars for atril to read.