Note 6 - Warrants - Warrants Outstanding (Details)	9 Months Ended
	Sep. 30, 2025 USD ($) $ / shares shares		Sep. 30, 2024 $ / shares shares
Warrants outstanding, balance (in shares) | shares	31,615,616		51,590,300
Warrants outstanding, Granted (in shares) | shares			4,127,516
Warrants outstanding, Exercised (in shares) | shares			(3,278,337)
Warrants outstanding, Expired (in shares) | shares	(2,634,698)		(20,534,700)
Warrants outstanding, balance (in shares) | shares	28,980,918		31,904,779
Weighted average remaining life, balance (Year)	1 year 9 months 18 days
Balance, aggregate intrinsic value | $	$ 2,000	[1]
Weighted Average [Member]
Weighted average price, balance (in dollars per share) | $ / shares	$ 0.29		$ 0.27
Weighted average price, Granted (in dollars per share) | $ / shares			0.27
Weighted average price, Exercised (in dollars per share) | $ / shares			0.24
Weighted average price, Expired (in dollars per share) | $ / shares	0.22		0.23
Weighted average price, balance (in dollars per share) | $ / shares	$ 0.29		$ 0.29

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