Help me lock down fully compensated ABGs ! what finally made it click for you

Hey y’all fundamentals student here studying my final on fluids/electrolytes and ABGs. I’ve got the basics down.

Where I keep getting stuck is fully compensated questions where the pH is sitting right around 7.40 (like 7.39 or 7.41). When both CO₂ and HCO₃ are off in the same direction, I get confused on which one is the cause vs. which is compensating.

Example that messed me up: pH 7.41, CO₂ 28, HCO₃ 17. Answer was fully compensated metabolic acidosis, but I picked respiratory alkalosis because the pH was barely on the alkalotic side.

For the nurses and senior students out there what finally made fully compensated ABGs click for you? Any shortcut, mnemonic, or way of looking at it that I’m missing?

Appreciate any wisdom 🙏