v3.26.1
Note 9 - Stock-Based Compensation - Fair Value Assumptions (Details) - The 2019 Stock Plan [Member] - $ / shares
6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Risk-free interest rate 3.90% 4.30%
Expected volatility 111.00% 113.50%
Expected life (years) (Year) 5 years 9 months 21 days 5 years 9 months 21 days
Market value per share on grant date (in dollars per share) $ 2.6 $ 2.73
Fair value per option on grant date (in dollars per share) $ 2.18 $ 2.32