Haha, i time out on WK a lot because of going through the forums, unfortunately it seems like you lose progress on any item where you only entered meaning or reading.
I use Wanikani Breeze Dark, having tried a few Dark Themes for WK.
I still use it with the Stylish extension, which needs a few fixes,
but a few days ago the author updated the script for the new dashboard,
and you can now apparently easily install it with Stylus,
while the other versions are not maintained anymore.