I'm looking for some information about how the Theming and Styles work on modern sites. But I don't find what I need.
In SharePoint Online modern sites, there doesn't seems to be a CSS file which we can use to use for example in a classic site. The Themes for example which are stored as JSON at the tenant level are (that's my guess) injected in the modern pages.
Where I work we understand how to inject CSS/styles (for example with modern or classic webparts or Extensions) but we would've like to know where the CSS of the Modern Pages is so we could use it in the Classic pages we will also have.
Is there any way to access those styles beside the PoweShell commands to get the JSON schema?