Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating activities
Net loss	$ (63,073)	$ (71,571)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	7,247	8,717
Depreciation	3,152	2,533
Amortization of right-of-use lease assets	2,041	3,036
Gain on lease modification	(1,590)	0
Accretion of discount on short-term investments	(1,255)	(46)
Long-lived asset impairment	182	1,900
Accretion of debt issuance costs	119	110
Lease incentives received	0	1,840
Changes in operating assets and liabilities:
Accounts receivable	382	514
Inventory, net	(1,622)	(940)
Prepaid expenses and other current assets	575	312
Other noncurrent assets	83	1,040
Accounts payable	(147)	(1,314)
Accrued expenses	(1,032)	370
Other current liabilities	(340)	139
Lease liabilities	(6,332)	(1,422)
Other noncurrent liabilities	81	37
Net cash used in operating activities	(61,529)	(54,745)
Investing activities
Purchases of short-term investments	(37,853)	(129,099)
Maturities of shot-term investments	135,553	122,846
Sales of short-term investments	169	19,987
Purchases of property and equipment	(33)	(578)
Net cash provided by investing activities	97,836	13,156
Financing activities
Proceeds from issuance of common stock under employee stock purchase plan	80	624
Proceeds from issuance of common stock under equity incentive plans	0	13
Repurchases of common stock under equity incentive plans	0	(13)
Net cash provided by financing activities	80	624
Net increase in cash and cash equivalents and restricted cash	36,387	(40,965)
Cash and cash equivalents and restricted cash, beginning of year	16,833	75,977
Cash and cash equivalents and restricted cash, end of year	53,220	35,012
Supplemental disclosure for cash activities
Interest paid	821	777
Supplemental disclosure for non-cash activities
Increase (decrease) in lease liability on lease modifications	(14,729)	19,475
Inventory transferred to property and equipment	1,643	6,498
Purchase of property and equipment included in accounts payable	447	0
Purchases of inventory included in accounts payable	135	647
Vesting of common stock issued for early exercise of stock options	$ 65	$ 300