h5p have got some odd choices for style elements that I'd like to be able to replace by overriding them in stylesheets.
doesn't seem to be possible to override h5p styles at this time, and the 'official' response from h5p is to use the https://github.com/h5p/h5pmods-moodle-plugin which doesn't work anymore. I've got a new stock standard moodle 391 site, with a single course and a single h5p activity. I can't use regular css overrides anywhere because they don't apply within the content iframe the h5p activity plays in.
I discovered that h5p content types have style references in the database and I tried to figure out if I could override these. I can see that `embed.php` has a `$h5pplayer->add_assets_to_page();` which has a `$this->get_assets();` which calls `$this->get_dependency_files();` which does both `loadContentDependencies` for the content required scripts and styles and `getDependenciesFiles` for the statically referenced files. the h5p_libraries table has names of scripts and styles and a "drop library css" column which the comment says is a "machine name for the librarys that are to drop their css" - errhm, what? Anyway I can't just dump styles in here and hope they apply - so these database fields are of no help and it's a rabbit hole I needn't have gone down.
The core styles come from a function in the h5p helper class called `get_core_assets` and this ideally where'd like like there to be some way to override or append styles. These are statically defined arrays inside class `H5PCore`so there's not much I can do there either without manually changing core code.