Sort each card onto a pile. The rule is secret — and it changes without warning.

✓ and ✗ are your only teachers. When ✓ turns to ✗, let the old rule go.

Your first run finds your level: it adapts and gets harder on purpose — hitting your ceiling IS the measurement. You can't fail a calibration.

🔓 Next unlock at Lv 40: Depth I — The field grows denser — more to hold, more to filter, same clock