Note 5 - Stockholders' Equity, Equity Incentive Plans, And Stock-Based Compensation - Valuation Assumptions (Details) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Expected dividend yield | 0.00% | 0.00% |
| Minimum [Member] | ||
| Risk-free interest rate | 3.70% | 3.40% |
| Expected term (in years) (Year) | 5 years 4 months 24 days | 5 years |
| Expected volatility | 110.00% | 111.00% |
| Maximum [Member] | ||
| Risk-free interest rate | 4.40% | 4.20% |
| Expected term (in years) (Year) | 6 years 1 month 6 days | 5 years 7 months 6 days |
| Expected volatility | 130.00% | 118.00% |