Errors in JetBrains IDE for legitimate Jekyll syntax

In my JetBrains IDEs (WebStorm, InteliJ, PyCharm, etc.) Jekyll front matter in CSS and SCSS and other files are marked as errors.

PyCharm also marks numerous other legal Jekyll constructs (@import using file name only, Liquid variables, etc.) as errors or warnings; so help with those would be appreciated too.

How do I configure my IDEs (PyCharm will do) so that I can develop a Jekyll site without spurious errors?

not sure, but maybe you just need some plugins to handle markdown and liquid?

This page has some info (2017):

No, the Liquid plugin does nothing (except for liquid files) and that article doesn’t really say anything relevant. There are no other plugins for JetBrains in the marketplace that show up on searches for Jekyll or Liquid.