Revert theming_customcss changes

I have done some mistakes while trying to adjust CSS from customcss app and Nextcloud became not usable with customcss app enabled.

I was able to delete theming_customcss directory from the server and then disable app in web ui but after re-enabling it loads back my broken custom css.

Where can i find my css modifications on the server so i can remove the part that broke my instance?