Hide Content Only Works For Non-Proof Directives, here

[schwabts]

Describe the bug

context
When I add the class dropdown to any directive except

````{prf:proof}
:class: dropdown
````

the directives become collapsible in the HTML output opened in a browser.

expectation
I expected the feature to work for actual proofs, too.

bug

• But instead I only succeed creating collapsible remarks, corollaries, notes, lemmas, theorems, ....
• Additional tests suggest the feature may not work in these two situations, either:
  1. anywhere in the markdown file after a prf:proof directive had been used
  2. directives that have a caption as in ````{prf:lemma} caption to be shown as Lemma 1 (caption)
• I did not find any error message possibly related to this.

problem
This is a problem for people creating lectures or slides for talks because hiding proofs is often of greater interest than hiding theorems when we want to convey the concepts.

Reproduce the bug

1. Create a Jupyter Book making use of sphinx-proof
2. Add the directives

````{prf:theorem}
:class: dropdown

All natural numbers are small.
````

and

````{prf:proof}
:class: dropdown

* $1$ Is small.
* If $n$ is small then $S(n)$, the successor of $n$ is small.
* By induction, all natural numbers are small.
````

3. jb build book/

List your environment

Jupyter Book : 0.13.0
External ToC : 0.2.4
MyST-Parser : 0.15.2
MyST-NB : 0.13.2
Sphinx Book Theme : 0.3.3
Jupyter-Cache : 0.4.3
NbClient : 0.5.3

[lellmann]

Same issue here. I think it might be because "proof" doesn't have a title line that can be made clickable? Maybe it would be useful to add an option to provide a title to the "Proof" block.