night mode suggestion

There is such an extension on Firefox that makes every white color to become black. I don't know it's name but it should be simple

There is already a script for it, you can find it here.

everyone will send u link on browser extension... but well it would be great have original black theme for SG and ST (esp for phones)

If you have the ESGST extension (which everyone should have because it's awesome in so many ways) you can find SquishedPotatoe's dark and dark grey themes in section 10 of the settings.