Common stock - Stock for issuance (Details) - shares	Mar. 31, 2025	Dec. 31, 2024
Common stock
Stock options issued and outstanding under the Plans	11,498,848	11,990,781
Total reserved common stock	18,495,387	15,528,401
2020 Equity Incentive Plan
Common stock
Remaining shares available for issuance under the Plans and ESPP	5,445,680	2,631,369
ESPP
Common stock
Remaining shares available for issuance under the Plans and ESPP	1,550,859	906,251