Note 11 - Equity Incentive Plans - Summary of Stock Option Transactions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Shares available for grant, balance (in shares)	12,074,692	5,582,742
Number of options outstanding, beginning balance (in shares)	14,725,261	10,216,106
Weighted average exercise price, balance (in dollars per share)	$ 4.48	$ 4.96
Shares availabe for grant, 2019 Plan Amendment (in shares)		12,000,000
Shares available for grant, granted (in shares)	(10,631,320)	(7,291,935)
Number of options outstanding, granted (in shares)	7,399,849	6,376,657
Weighted average exercise price, granted (in dollars per share)	$ 0.78	$ 4.1
Number of options outstanding, exercised (in shares)	(54,720)	(180,336)
Weighted average exercise price, exercised (in dollars per share)	$ 0.31	$ 1.24
Shares available for grant, forfeited (in shares)	2,444,486	1,625,133
Number of options outstanding, forfeited (in shares)	(2,139,887)	(1,518,230)
Weighted average exercise price, forfeited (in dollars per share)	$ 5	$ 6.19
Shares available for grant, canceled (in shares)	1,797,948	158,752
Number of options outstanding, canceled (in shares)	(1,991,777)	(168,936)
Weighted average exercise price, canceled (in dollars per share)	$ 4.51	$ 7.17
Shares available for grant, balance (in shares)	5,685,806	12,074,692
Number of options outstanding, balance (in shares)	17,938,726	14,725,261
Weighted average exercise price, balance (in dollars per share)	$ 2.9	$ 4.48
Restricted Stock Units (RSUs) [Member]
Number of options outstanding, beginning balance (in shares)	808,310
Weighted average exercise price, balance (in dollars per share)	$ 3.57	$ 0
Number of options outstanding, granted (in shares)		915,278
Weighted average exercise price, granted (in dollars per share)	0.78	$ 3.58
Weighted average exercise price, exercised (in dollars per share)	1.09	$ 0
Number of options outstanding, forfeited (in shares)		(106,968)
Weighted average exercise price, forfeited (in dollars per share)	2.42	$ 3.62
Weighted average exercise price, canceled (in dollars per share)	$ 0	$ 0
Granted (in shares)	3,231,471
Exercised (in shares)	(1,608,809)
Forfeited (in shares)	(304,599)
Number of options outstanding, balance (in shares)		808,310
Weighted average exercise price, balance (in dollars per share)	$ 1.37	$ 3.57
Balance at December 31, 2023 (in shares)	2,126,373