My favorite theme, black borders and simple.

not transparent

very neat!
no borders!

i have the latest firefox version and it only works on the right side

Good stuff, I love Dark Mode related themes and this is perfect.

Super nice!
With no lining around open tab.
Just purrfect! :)

Update: lining does not appear when using Waterfox and oddly enough, not even on SpiralLinux!

Looks awesome!!