[pjerem]

It depends on your own issue but :

- https://addons.mozilla.org/fr/firefox/addon/font-contrast-fi...

- https://addons.mozilla.org/fr/firefox/addon/darkreader

Or anything that can change or override the default browser style-sheet. Be it yourself if you are technical savvy enough or a tool.

It can also just be your monitor settings if it suits you.

[zagrebian]

I’m not sure that such browser extensions resolve websites from accommodating users with eyestrain/headaches. At the very least, a website with a shrill design should be compatible with the browsers’ reader modes, and the website in question isn’t.