Style of headings

[jenniferward]

I've tried to be consistent in formatting the headers for different kinds of sections but now on the website my eyes get lost easily.

For example:
https://guidelines-stage.rism.info/institutions.html#in_numbers
In my editor I have a 3rd level and 4th level for the headings:
### Authority reference (024)
#### Authority reference (024 $a)

But on the page, it is hard to see where the headings start because it is all grey.

Would it be enough to just make the headings bold?
Or should the main points be level 2 headings? On this page, Language is level 2 and I like the underline:

But maybe bold here too.