jupyterlab overrides font size to 14px

[f0k]

Description

It seems that the font-size in presentation mode is overridden to 14px. The style inspector shows:

The style in question can be traced back to rendermime's base.css, with the --jp-content-font-size1 defined in variables.css. For some reason it takes precedence over the reveal style sheet. I can override it with a custom rise.css that has:

.jp-RenderedHTMLCommon { font-size: 42px }

But I assume this is not how it's meant to be.

Reproduce

Install jupyterlab_rise, launch jupyter lab:

uv run --with jupyterlab_rise jupyter lab

Create a notebook with some markdown text without further formatting, open a RISE presentation. The font size is 14px, the same as in the notebook editor.

Expected behavior

The font size should be much larger than in the notebook editor.

Context

On June, 17 it still worked correctly. Since then, I've updated from Ubuntu 22.04 with a globally pip-installed:

jupyterlab==4.2.0
jupyterlab_rise==0.42.0
jupyterlab_server==2.27.1

to Ubuntu 24.04 with a locally uv-installed:

jupyterlab==4.4.9
jupyterlab-rise==0.43.1
jupyterlab-server==2.27.3

Just downgrading to my previous set of jupyter-named packages doesn't change anything:

uv run --with jupyterlab==4.2.0 --with jupyterlab_rise==0.42.0 --with jupyterlab_pygments==0.3.0 --with jupyterlab_widgets==3.0.10 --with jupyter_server==2.12.5 --with jupyter_client==7.4.9 --with jupyter_core==5.1.3 --with jupyter_events==0.9.0 jupyter lab

Primarily I am looking for feedback whether anybody else observed this, or on ideas what else could have changed. Then the next step will be to figure out how to solve it.