On github.com, with the default GitHub stylesheet, the <details> tag only has cursor: pointer if a <summary> tag is included explicitly. If there is no <summary> tag, the cursor does not indicate that the dropdown is clickable. Here is an example of the incorrect style:
This is a test
The code for this incorrect version is:
<details>
This is a test
</details>
Compare that to explicitly including a <summary> tag, which behaves the way it is supposed to:
Details
This is another test
The code for the second example is:
<details>
<summary>Details</summary>
This is another test
</details>
This can be fixed by adding the following CSS to the stylesheet:
In my browser (Firefox 85.0.2 (64-bit)), it’s actually happening in the post above – I think the github.community stylesheet has the same issue. I can still provide screenshots of it happening on github.com though, and can also provide a Gist demo if that is preferable.
@jstrieb thanks for the thorough breakdown of this issue.
I have reported this to our engineering team.
I can’t say when this will be fixed, and when it does it will likely not have any mention in a changelog. Please be assured that this information has been delivered to the proper team.