This is trippy, what is this?

So. I have the windows "high contrast black" theme applied, with a few minor tweaks, because I think it looks cool. Anyways, when I go to a google search result page, the links (blue) seem to be hovering above the other text (green). It's like 3d. The search results are popping out at me. Any ideas what this could be? And no, I'm not high. xD