There are extensions that allow a global dark mode feature.
https://addons.mozilla.org/en-CA/firefox/addon/dark-mode-webextension/
https://chrome.google.com/webstore/detail/dark-mode/dmghijelimhndkbmpgbldicpogfkceaj?hl=en
There are extensions that allow a global dark mode feature.
https://addons.mozilla.org/en-CA/firefox/addon/dark-mode-webextension/
https://chrome.google.com/webstore/detail/dark-mode/dmghijelimhndkbmpgbldicpogfkceaj?hl=en