>What's wrong with the icons being GIFs?

Nothing necessarily in this case, I just assumed that a vector image format would be much smaller and obviously scales with the resolution (how much that matters for the arrows, I don't know).

You don't even need images — just use unicode arrow or triangle characters. e.g. ▲

>You don't even need images — just use unicode arrow or triangle characters. e.g. ▲

I see, personally I'd prefer this for aesthetic reasons as well!

The site also uses tables for layout. It's bare bones but it works.