Accounts receivable, net (Details 1) |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
|
Jun. 30, 2026
USD ($)
|
Jun. 30, 2026
CNY (¥)
|
Dec. 31, 2023
CNY (¥)
|
|
| Credit Loss [Abstract] | |||
| Beginning balance | $ 784,383 | ¥ 5,513,270 | ¥ 4,030,967 |
| Allowance for credit loss | 15,724 | 108,423 | 2,306,700 |
| Write-off | (273,180) | (1,883,741) | (51,892) |
| Other changes - Deconsolidation | (80,461) | (554,823) | (772,505) |
| Exchange rate difference | 20,892 | ||
| Ending balance | $ 467,358 | ¥ 3,183,129 | ¥ 5,513,270 |