v3.26.1
Note 5 - Share-based Compensation - Stock Options (Details) - USD ($)
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
2024 Equity Incentive Plan [Member]    
Options outstanding, balance (in shares) 16,793,014 5,493,920
Weighted average exercise price, balance (in dollars per share) $ 0.21 $ 0.23
Options outstanding, Granted (in shares) 6,781,011 3,790,347
Weighted average exercise price, Granted (in dollars per share) $ 0.13 $ 0.24
Unvested (in shares) (5,299,487) (2,770,232)
Weighted average exercise price per share, unvested (in dollars per share) $ 0.18 $ 0.23
Options outstanding, Forfeited (in shares) (87,221)  
Weighted average exercise price, Forfeited (in dollars per share) $ 0.19  
Weighted average remaining term, Outstanding (Year) 9 years  
Aggregate intrinsic Value, Balance [1] $ 0  
Vested balance (in shares) 18,187,317 6,514,035
Weighted average exercise price, Vested (in dollars per share) $ 0.19 $ 0.24
Weighted average remaining term, Vested (Year) 8 years 10 months 24 days  
Aggregate intrinsic value, Vested [1] $ 0  
Options outstanding, Vested (in shares) 18,187,317 6,514,035
Weighted average exercise price, Vested (in dollars per share) $ 0.19 $ 0.24
Options outstanding, balance (in shares) 23,486,804 9,284,267
Weighted average exercise price, balance (in dollars per share) $ 0.19 $ 0.24
2018 Equity Incentive Plan [Member]    
Options outstanding, balance (in shares) 41,604,435 42,171,386
Weighted average exercise price, balance (in dollars per share) $ 0.19 $ 0.19
Unvested (in shares) (1,369,387) (2,281,725)
Weighted average exercise price per share, unvested (in dollars per share) $ 0.23 $ 0.23
Weighted average remaining term, Outstanding (Year) 5 years 3 months 18 days  
Aggregate intrinsic Value, Balance [2] $ 0  
Vested balance (in shares) 40,235,048 39,322,710
Weighted average exercise price, Vested (in dollars per share) $ 0.19 $ 0.19
Weighted average remaining term, Vested (Year) 5 years 3 months 18 days  
Aggregate intrinsic value, Vested [2] $ 0  
Options Outstanding, Exercised (in shares) 0 (566,951)
Weighted average exercise price, Exercised (in dollars per share) $ 0 $ 0.16
Options outstanding, Vested (in shares) 40,235,048 39,322,710
Weighted average exercise price, Vested (in dollars per share) $ 0.19 $ 0.19
Options outstanding, balance (in shares) 41,604,435 41,604,435
Weighted average exercise price, balance (in dollars per share) $ 0.19 $ 0.19
The 2007 Equity Incentive Plan [Member]    
Options outstanding, balance (in shares) 380,000 1,157,500
Weighted average exercise price, balance (in dollars per share) $ 0.63 $ 0.53
Weighted average remaining term, Outstanding (Year) 7 months 6 days  
Aggregate intrinsic Value, Balance [1] $ 0  
Options outstanding, balance (in shares) 340,000 680,000
Weighted average exercise price, balance (in dollars per share) $ 0.65 $ 0.61
Options outstanding, Expired (in shares) (40,000) (477,500)
Weighted average exercise price per share, Expired (in dollars per share)   $ 0.42
The 2007 Equity Incentive Plan [Member] | Minimum [Member]    
Weighted average exercise price per share, Expired (in dollars per share) $ 0.45  
Non Plan [Member]    
Options outstanding, balance (in shares) 14,039,129 15,687,642
Weighted average exercise price, balance (in dollars per share) $ 0.39 $ 0.4
Options outstanding, Granted (in shares)   32,143
Weighted average exercise price, Granted (in dollars per share)   $ 0.28
Unvested (in shares) (187,500) (218,750)
Weighted average exercise price per share, unvested (in dollars per share) $ 0.18 $ 0.44
Options outstanding, Forfeited (in shares)   (1,363,818)
Weighted average remaining term, Outstanding (Year) 1 year 4 months 24 days  
Vested balance (in shares) 13,185,052 14,137,217
Weighted average exercise price, Vested (in dollars per share) $ 0.39 $ 0.4
Weighted average remaining term, Vested (Year) 1 year 3 months 18 days  
Aggregate intrinsic value, Vested [1] $ 0  
Options outstanding, Vested (in shares) 13,185,052 14,137,217
Weighted average exercise price, Vested (in dollars per share) $ 0.39 $ 0.4
Options outstanding, balance (in shares) 13,372,552 14,355,967
Weighted average exercise price, balance (in dollars per share) $ 0.38 $ 0.39
Options outstanding, Expired (in shares) (666,577)  
Weighted average exercise price per share, Expired (in dollars per share) $ 0.42 $ 0.35
Aggregate intrinsic value, balance [1] $ 0  
[1] Aggregate intrinsic value based on closing common stock price of $0.16 at March 31, 2026.
[2] Aggregate intrinsic value based on closing common stock price of $0.16 at March 31, 2026