Note 10 - Equity Incentive Plans - Summary of Stock Option Transactions (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2024	Jun. 30, 2023
Shares available for grant, balance (in shares)		5,685,806	5,685,806
Number of options outstanding, beginning balance (in shares)		17,938,726	17,938,726
Weighted average exercise price, balance (in dollars per share)		$ 2.9	$ 2.9
Shares available for grant, granted (in shares)			(7,135,230)
Number of options outstanding, granted (in shares)			5,226,937
Weighted average exercise price, granted (in dollars per share)			$ 1.12
Number of options outstanding, exercised (in shares)			(26,980)	(54,720)
Weighted average exercise price, exercised (in dollars per share)			$ 0.78
Number of RSUs outstanding, release (in shares)			(526,424)
Released, Weighted average grant date fair value (in dollars per share)		$ 1.39
Shares available for grant, forfeited (in shares)			1,659,141
Number of options outstanding, forfeited (in shares)			(1,286,857)
Weighted average exercise price, forfeited (in dollars per share)			$ 2.2
Shares available for grant, canceled (in shares)			139,252
Number of options outstanding, canceled (in shares)			(152,023)
Weighted average exercise price, canceled (in dollars per share)			$ 5.2
Shares available for grant, balance (in shares)	18,348,969		18,348,969
Number of options outstanding, balance (in shares)	21,699,803		21,699,803
Weighted average exercise price, balance (in dollars per share)	$ 2.5		$ 2.5
The 2024 Inducement Award Plan [Member]
Authorized (in shares)			3,000,000
The 2019 Plan [Member]
Authorized (in shares)			15,000,000
Restricted Stock Units (RSUs) [Member]
Number of RSUs outstanding (in shares)		2,126,373	2,126,373
Balance, Weighted average grant date fair value (in dollars per share)	$ 1.21	$ 1.37	$ 1.37
Number of RSUs outstanding, granted (in shares)			1,908,293
Granted, Weighted average grant date fair value (in dollars per share)		1.14
Number of RSUs outstanding, forfeite (in shares)			(372,284)
Forfeited, Weighted average grant date fair value (in dollars per share)		1.49
Number of RSUs outstanding (in shares)	3,135,958		3,135,958
Balance, Weighted average grant date fair value (in dollars per share)		$ 1.21