Share-based compensation - Share-based Compensation Expense (Details) - USD ($) |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | ||
| Total share-based compensation expenses | $ (116,394) | $ 76,306 |
| Selling and distribution expenses | ||
| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | ||
| Total share-based compensation expenses | 17,568 | 29,754 |
| General and administrative expenses | ||
| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | ||
| Total share-based compensation expenses | $ (133,962) | $ 46,552 |