Note 11 - Warrants - Outstanding and Exercisable (Details) - $ / shares	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Mar. 31, 2025
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0	$ 0	$ 0.2
Outstanding, shares (in shares)		200,000	200,000
Class of Warrant or Right, Outstanding (in shares)	0	0	200,000
Outstanding, Weighted Average Exercise Price (in dollars per share)		$ 0.2	$ 0.2
Class of Warrant or Right, Exercisable (in shares)	0	0	200,000
Issued, shares (in shares)		0	0
Issued, Weighted Average Exercise Price (in dollars per share)		$ 0	$ 0
Exercised, shares (in shares)		0	0
Exercised, Weighted Average Exercise Price (in dollars per share)		$ 0	$ 0
Expired, shares (in shares)		(200,000)	0
Expired, Weighted Average Exercise Price (in dollars per share)		$ 0.2	$ 0
Cancelled, shares (in shares)		0	0
Cancelled, Weighted Average Exercise Price (in dollars per share)		$ 0	$ 0
Outstanding, shares (in shares)	0	0	200,000
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0	$ 0	$ 0.2
Exercisable, Weighted Average Exercise Price (in dollars per share)	0	0	$ 0.2
Warrant One [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0	$ 0
Class of Warrant or Right, Outstanding (in shares)	0	0
Class of Warrant or Right, Outstanding, Weighted Average Remaining Contractual Life (Year)	0 years
Class of Warrant or Right, Exercisable (in shares)	0	0
Outstanding, shares (in shares)	0	0
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0	$ 0