The best!

Very Good for someone with Insomnia & Seasonal Depression, keeps my rhythms in order.

the dark theme can protect eyes efficiently,and I don't find a greater theme addon yet.

It works every time

very nice & smart dark color style, suitable for almost all websites.

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except that it modifies the firefox tab bar look, which deactivate my firefox theme.
// It would be nice if has option to disable this feature
// using in ubuntu20 darkmode, firefox 96

This add-on works with google maps, Amazon, and basically all the websites I use daily! And dark mode is done very tastefully. I'm really impressed.