i disappeared GTK4 Widget Factory with CSS :)

basically whats new here is the GSK Renderer info, plus a quick view on GTK inspector CSS, if you haven't seen it for whatever reason

to enable GTK inspector open DConf Editor and goto
org➞gtk➞settings➞debug and enable inspector keybinding

after that you can fire it on any GTK3/4 app with Shift+Ctl+i/d

also from command line you can run it like that:
GTK_DEBUG=interactive nautilus