Stock-based compensation - Employee Stock Purchase Plan (Details) - Shares committed under the 2021 ESPP		12 Months Ended
	May 25, 2021	Dec. 31, 2024 USD ($) calendarYear $ / shares shares	Dec. 31, 2023 USD ($) $ / shares	Dec. 31, 2022 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Offering period (in months)	6 months
accumulated payroll deductions at discount (as percent)	15.00%
Percentage of the fair market value of common stock	85.00%
Maximum employee payroll deduction (as percent)	15.00%
Aggregate value of shares purchased		$ 25,000
Eligible employee compensation		$ 800,000	$ 1,000,000
Shares reserved for future issuance (in shares) | shares		5,588,043
Number of authorized share increases (in years) | calendarYear		10
Percentage of outstanding stock		1.00%
Shares authorized for issuance (in shares) | shares		16,000,000
Average grant date fair value for offering periods under 2021 ESPP (in dollars per share) | $ / shares		$ 4.68	$ 4.63	$ 8.28
Expected dividend yield		0.00%	0.00%	0.00%
Unrecognized compensation expense		$ 500,000
Weighted average period over which unrecognized compensation expense would be recognized (in months)		4 months