Any way to save my eyes at night? - sh.itjust.works

I love this app but have one issue: web links open to a blinding white screen a second, then they don’t use dark mode like the rest of the system (this is on iOS). I would love to be able to use my own browser for links instead of the built in one, and if that’s not possible, have reader mode set as default (it displays the page in dark mode). Maybe I’m just missing a setting somewhere?