Accounts receivable and allowance for credit losses (Details 1) |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
|
Jun. 30, 2026
USD ($)
|
Jun. 30, 2026
CNY (¥)
|
Dec. 31, 2025
CNY (¥)
|
|
| Credit Loss [Abstract] | |||
| Beginning balance | |||
| Addition | 11,012 | 75,000 | |
| Recovery | 11,012 | 75,000 | |
| Ending balance | |||