Note 11 - Stockholder's Equity - Fair Value of Stock Options (Details) - Share-Based Payment Arrangement, Option [Member] - $ / shares |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Weighted-average FV (in dollars per share) | $ 1.16 | $ 1.23 |
| Minimum [Member] | ||
| Expected volatility | 85.34% | 88.38% |
| Expected term (Years) (Year) | 5 years | 6 years 6 months |
| Risk-free interest rate | 3.82% | 4.06% |
| Maximum [Member] | ||
| Expected volatility | 90.91% | 89.35% |
| Expected term (Years) (Year) | 6 years 6 months | 7 years |
| Risk-free interest rate | 4.15% | 4.14% |