[mintplant]

I thought of that, but then the arrows don't hide immediately after you click them as on HN - they'd still be visible until the request completes. So you'd end up with the same problem: hiding both arrows when either is clicked without using JS.

(I assume you mean putting each pair of arrows in an <iframe>, rather than each individual arrow.)

[microcolonel]

If it's a button, it'll be in the :focused state, you can use that to style it. Or you could use a CSS transition with a very very long time in one direction on the :active state.

And of course, you can use adjacency selectors with buttons, while you can't with :visited links.

[mintplant]

That's exactly what I did, though :P

Check my first comment.