Note 5 - Share-based Compensation - Stock Options (Details) - USD ($)		3 Months Ended					6 Months Ended
		Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024		Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
2024 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		9,284,267	5,493,920	1,829,757		0	5,493,920	0
Weighted average exercise price, balance (in dollars per share)		$ 0.23	$ 0.23	$ 0.26		$ 0	$ 0.23	$ 0
Options outstanding, Granted (in shares)			3,790,347			1,829,757
Weighted average exercise price, Granted (in dollars per share)			$ 0.24			$ 0.26
Unvested (in shares)		(2,770,232)		(423,868)			(2,770,232)	(423,868)
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.23		$ 0.26			$ 0.23	$ 0.26
Aggregate intrinsic value, Vested		$ 29,000			[1]		$ 29,000		[1]
Weighted average remaining term, Outstanding (Year)		9 years 6 months
Aggregate intrinsic Value, Balance	[1]	$ 29,000					$ 29,000
Vested balance (in shares)		6,514,035		1,405,889			6,514,035	1,405,889
Weighted average exercise price, Vested (in dollars per share)		$ 0.24		$ 0.26			$ 0.24	$ 0.26
Weighted average remaining term, Vested (Year)		9 years 6 months
Options outstanding, Vested (in shares)		6,514,035		1,405,889			6,514,035	1,405,889
Weighted average exercise price, Vested (in dollars per share)		$ 0.24		$ 0.26			$ 0.24	$ 0.26
Options outstanding, balance (in shares)			9,284,267			1,829,757
Weighted average exercise price, balance (in dollars per share)			$ 0.23			$ 0.26
2018 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		41,604,435	42,171,386	42,159,362		41,108,448	42,171,386	41,108,448
Weighted average exercise price, balance (in dollars per share)		$ 0.19	$ 0.19	$ 0.19		$ 0.19	$ 0.19	$ 0.19
Options outstanding, Granted (in shares)						1,547,938
Weighted average exercise price, Granted (in dollars per share)						$ 0.3
Unvested (in shares)		(2,281,725)		(4,087,382)			(2,281,725)	(4,087,382)
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.23		$ 0.22			$ 0.23	$ 0.22
Aggregate intrinsic value, Vested	[1]	$ 1,127,000					$ 1,127,000
Weighted average remaining term, Outstanding (Year)			6 years 3 months 18 days
Aggregate intrinsic Value, Balance	[1]		$ 1,165,000
Vested balance (in shares)		39,322,710		38,071,980			39,322,710	38,071,980
Weighted average exercise price, Vested (in dollars per share)		$ 0.19		$ 0.19			$ 0.19	$ 0.19
Weighted average remaining term, Vested (Year)		6 years 3 months 18 days
Options Outstanding, Exercised (in shares)		(566,951)				(497,024)	(566,951)
Weighted average exercise price, Exercised (in dollars per share)		$ 0.16				$ 0.15
Options outstanding, Vested (in shares)		39,322,710		38,071,980			39,322,710	38,071,980
Weighted average exercise price, Vested (in dollars per share)		$ 0.19		$ 0.19			$ 0.19	$ 0.19
Options outstanding, balance (in shares)			41,604,435			42,159,362
Weighted average exercise price, balance (in dollars per share)			$ 0.19			$ 0.19
The 2007 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)			1,157,500			1,564,085	1,157,500	1,564,085
Weighted average exercise price, balance (in dollars per share)			$ 0.53			$ 0.61	$ 0.53	$ 0.61
Weighted average remaining term, Outstanding (Year)		1 year
Aggregate intrinsic Value, Balance	[1]	$ 0					$ 0
Options outstanding, balance (in shares)		680,000		720,000			680,000	720,000
Weighted average exercise price, balance (in dollars per share)		$ 0.61		$ 0.6			$ 0.61	$ 0.6
Options outstanding, Expired (in shares)							(477,500)	(844,085)
Weighted average exercise price per share, Expired (in dollars per share)								$ 0.61
The 2007 Equity Incentive Plan [Member] | Minimum [Member]
Weighted average exercise price per share, Expired (in dollars per share)							$ 0.42
Non Plan [Member]
Options outstanding, balance (in shares)		14,355,967	15,687,642	16,398,777		17,375,044	15,687,642	17,375,044
Weighted average exercise price, balance (in dollars per share)		$ 0.39	$ 0.4	$ 0.4		$ 0.39	$ 0.4	$ 0.39
Options outstanding, Granted (in shares)			32,143			15,686
Weighted average exercise price, Granted (in dollars per share)			$ 0.28			$ 0.26
Unvested (in shares)		(218,750)		(437,500)			(218,750)	(437,500)
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.44		$ 0.45			$ 0.44	$ 0.45
Aggregate intrinsic value, Vested	[1]	$ 73,000					$ 73,000
Weighted average remaining term, Outstanding (Year)			2 years 2 months 12 days
Vested balance (in shares)		14,137,217		15,961,277			14,137,217	15,961,277
Weighted average exercise price, Vested (in dollars per share)		$ 0.4		$ 0.39			$ 0.4	$ 0.39
Weighted average remaining term, Vested (Year)		2 years 2 months 12 days
Options Outstanding, Exercised (in shares)						(463,882)
Weighted average exercise price, Exercised (in dollars per share)						$ 0.54
Options outstanding, Vested (in shares)		14,137,217		15,961,277			14,137,217	15,961,277
Weighted average exercise price, Vested (in dollars per share)		$ 0.4		$ 0.39			$ 0.4	$ 0.39
Options outstanding, balance (in shares)			14,355,967			16,398,777
Weighted average exercise price, balance (in dollars per share)			$ 0.39			$ 0.4
Weighted average exercise price per share, Expired (in dollars per share)			$ 0.35			$ 0.17
Options outstanding, Expired (in shares)			(1,363,818)			(528,071)
Aggregate intrinsic value, balance	[1]		$ 73,000

[1] Aggregate intrinsic value based on closing common stock price of $0.21 at June 30, 2025.