Note 10 - Equity Incentive Plans - Assumptions of Options (Details) - Share-Based Payment Arrangement, Option [Member] |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Risk-free interest rate | 3.90% | |||
| Expected term (in years) (Year) | 6 years | 6 years | ||
| Expected volatility | 118.40% | 126.50% | ||
| Minimum [Member] | ||||
| Risk-free interest rate | 4.10% | 3.80% | 3.70% | |
| Expected term (in years) (Year) | 5 years 6 months | 5 years 6 months | ||
| Expected volatility | 125.60% | 128.90% | ||
| Maximum [Member] | ||||
| Risk-free interest rate | 4.40% | 4.40% | 4.40% | |
| Expected term (in years) (Year) | 6 years | 6 years | ||
| Expected volatility | 128.60% | 130.80% | ||