I don't know why my comment was downvoted, but it was a genuine question to understand the purpose of the project.

Likely because just "why?" can come off as flip rather than indicating actual interest. Text-only forums can make it hard to show where you're coming from with such a short response. Perhaps if you include a reason why you think it might be a bad idea, or speculate what might motivate their effort it would show your interest.

Is there a down vote button here? I see only the up vote.

It is hard to say what the purpose is. At first I do this just for fun.

Maybe you could consider it as a trial to use CSS to simulate native UI, although not perfectly.

There's a minimum number of karma needed (20 I think) to be able to downvote.

I have >20 karma and can't downvote.

If you can't downvote at all, then I likely have the threshold wrong. This thread makes me think it's 200 or 500.

https://news.ycombinator.com/item?id=8381148

Two other factors I know of are:

- You can't downvote a response to a comment you posted

- You can't downvote comments after a certain interval (24 hours?)

-