GTK-3 CSS tags/ids/classes names reference?

[Fabrice Delente <delentef gmail com>]

Hello.

I'm trying to change by CSS the colors of the tabs that appear at the
top of a GtkFileChooserWidget and that show the path for the current
folder (typically, it has an icon for the filesystem then e.g. home
user myFolder in the different tabs).

I haven't been able to find documentation about the tags/classes names
to use in the CSS file for these elements; more broadly, is there
somewhere a reference document for all the CSS tags that mark every
element in every GTK widget? Thanks !