Right-of-use assets and lease liabilities - Other information (Details) |
6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2026
CNY (¥)
|
Jun. 30, 2026
USD ($)
|
Jun. 30, 2025
CNY (¥)
|
Dec. 31, 2025
CNY (¥)
|
|
| Right-of-use assets and lease liabilities | ||||
| Operating cash flows used in operating lease | ¥ 252,223 | $ 37,173 | ¥ 916,061 | |
| Right-of-use assets obtained in exchange for new operating lease liabilities | ¥ 663,702 | $ 97,818 | ¥ 1,303,459 | |
| Right-of-use assets obtained in exchange for operating lease liabilities from modification | ¥ 1,198,602 | |||
| Weighted-average remaining lease term-operating | 3 years | 3 years | 2 years | |
| Weighted-average discount rate-operating | 3.20% | 3.20% | 3.20% | |