Weird Sidebar Behavior

[chillerb]

Describe the bug

context
When toggling the primary sidebar...

expectation
...I expected the sidebar to fold in and disappear...

bug
...but instead, the sidebar becomes a weird overlay.

problem
For some reason, the sidebar behaves as expected when building and hosting the book locally.
But when the book is deployed via GitHub Pages, the sidebar behaves weird.
I suspect, the issue is, that some css isn't found.
Perhaps due to the book not being hosted on the root domain.
Maybe I missed something relevant in the config file?
See the repository:
https://github.com/bckrlab/dsc-tutorials

Reproduce the bug

1. head to https://bckrlab.org/dsc-tutorials/intro.html
2. toogle the sidebar

List your environment

Python: 3.12

Jupyter Book : 1.0.3
External ToC : 1.0.1
MyST-Parser : 2.0.0
MyST-NB : 1.1.2
Sphinx Book Theme : 1.1.3
Jupyter-Cache : 1.0.0
NbClient : 0.10.0

[chillerb]

Also, it seems to work correctly in mobile mode?