Summary of significant accounting policies (Details 1) |
Jun. 30, 2026
USD ($)
|
Jun. 30, 2026
CNY (¥)
|
Dec. 31, 2025
CNY (¥)
|
|---|---|---|---|
| Defined Benefit Plan Disclosure [Line Items] | |||
| Total non-controlling interests | $ 1,858,425 | ¥ 12,657,550 | ¥ 5,173,851 |
| Ocean H K [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Total non-controlling interests | 8,485 | 57,793 | (2,001,657) |
| Hai Cloud Inc [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Total non-controlling interests | $ 1,849,940 | ¥ 12,599,757 | ¥ 7,175,508 |