Regression in agogo theme

[gvimont]

Describe the bug

Pull request #10520 introduced a regression in the display of the Table of Content of the agogo theme. The agogo sample can be seen here: https://sphinx-themes.org/sample-sites/default-agogo/

How to Reproduce

https://sphinx-themes.org/sample-sites/default-agogo/

The background's width of the Table of Contents takes the whole page.

Expected behavior

The background's width of the Table of Contents should be limited to the TOC width.

Your project

Internal

Screenshots

No response

OS

Linux

Python version

3.8

Sphinx version

5.1.0

Sphinx extensions

No response

Extra tools

No response

Additional context

No response

[gvimont]

This is not a regression but #10520 make visible a bug in agogo theme.

[mgeier]

I'm the author of #10520 and I must confess that I wasn't aware the agogo uses the wrong CSS class for its sidebar (sidebar instead of the sphinxsidebar) and it doesn't "correctly" style the sidebar directive.

So I agree that agogo was broken before but it is more broken after my change.