Slitherine

I just bought the game in the recent sale, and in my third try got into a dominating endgame position. I'm trying for a research victory. The tooltip says I need 75% of the techs researched, which I've had for at least 20 turns, and I'm up over 90% now (according to that same tooltip). But nothing's happening. How do I actually get the victory to register?

Dammit, if I'd known the game didn't actually have a manual, I probably wouldn't have bought it.

When it says you have 75% of the research-victory, then you have 75% of 75%, which is 56.25%.
Now that you are at 90% of 75% that is 67.5%.
So you are quite close already. Just hold out a few more turns.