It might be that it goes left to right instead of top down.

I'm having issues with this gradient too. (Though I'm running a fever after being vaccinated yesterday, so my perception might be different than usual today).

It feels like that optical illusion with disappearing background [1] where your brain attempts to re-tune itself, and it's kind of uncomfortable.

My screen width is 1280px.

[1] https://knowyourmeme.com/photos/834411-optical-illusion

It's a cool idea but I wrote a userstyle to override it. Reading on a plain color is easier for me

Hi! Sorry for the late reply.

Here's a screenshot of my screen from the time of writing the comment https://i.imgur.com/ngD1Xkj.png

I'm on a macbook pro 15.4-inch (2880 x 1800).

I see you've changed background, thank you for that! <3 Now it is far far better. Though I still find myself having to try harder to read the text on such color. I'm not sure of the reasons, though. Maybe it's me, maybe it's f.lux.

(though f.lux is on Movie Mode, meaning the dim and color correction are lighter than default)

P.S. I do not know of and never experienced any color perception problems.