The main issue I notice is that the up/down arrows and other UI elements are too tiny to easily/accurately tap with a touchscreen. Thankfully touchscreens are pretty good at guessing which HTML element my fat fingers are touching, but it still leaves me a bit paranoid about e.g. whether I upvoted or downvoted.

After you vote, look for whether the text next to the timestamp says "unvote" or "undown". That will tell you whether you upvoted or downvoted.

In tiny, gray text, with words that look similar to those with imperfect eyesight. It could easily be improved without breaking the site's entire aesthetic, IMO.

I never noticed "unvote" was exclusively used for upvotes. I had been thinking there was no way to check. Thank you.

It’s so bad on mobile that there’s a market of HN clients.

Myself I am writing this from an app I’ve bought on the App Store.