Theme geckium settings page according to selected design.

[Classic-Windows-69]

Before sending your suggestion

• My version of Firefox is up to date (for 115, this means being on at least 115.16.1)
• My copy of Geckium is up to date (no update option in the hamburger/spanner menu)

What browser are you running Geckium on?

Mozilla Firefox

What Operating System are you running Geckium on?

Windows 10 Version 22H2 (OS Build 19045.4894)

What would you like to suggest for Geckium?

Theme the Geckium settings page match with the selected layout, like what you managed to do with the regular settings page.

Additional Context

I've noticed that when using older layouts, the current Geckium settings page feels out of place.
Secondary suggestion: when using layouts where it would be accurate (such as the 1.0 layout for example), have the default settings page appear as a separate window with native tabs instead of a sidebar.

[angelbruni]

I personally think that Chromium's settings page is super boring, I kinda like the distinction between Geckium Settings and Chromium's.
I also find Material Design boring, but less boring. I would ditch it in an instant if anyone suggested a good design alternative that doesn't involve Android Holo or Google's Project Kennedy.
If you have any suggestions that don't involve re-using Chromium's settings page design, Android Holo or Google's Project Kennedy, go ahead.