Summary of significant accounting policies (Details 4) |
Jun. 30, 2025
USD ($)
|
Jun. 30, 2025
CNY (¥)
|
Dec. 31, 2024
CNY (¥)
|
|---|---|---|---|
| Total | $ 3,192,452 | ¥ 22,853,488 | ¥ 17,587,961 |
| Shanghai Weimu [Member] | |||
| Total | 651,203 | 4,661,702 | 4,495,040 |
| Viwo Tech [Member] | |||
| Total | $ 2,541,249 | ¥ 18,191,786 | ¥ 13,092,921 |