v3.26.3
Accounts receivable, net - Allowance for credit losses (Details)
6 Months Ended 12 Months Ended
Jun. 30, 2026
CNY (¥)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
CNY (¥)
Dec. 31, 2025
CNY (¥)
Allowance for credit loss [Roll Forward]        
Allowance for credit losses at beginning of the year ¥ 887,898 $ 130,860 ¥ 102,200 ¥ 102,200
Additions charged to expense 1,430,109 210,772   785,698
Allowance for credit losses at end of the year 2,318,007 341,632   ¥ 887,898
Allowance for accounts receivable ¥ 1,430,109 $ 210,772 ¥ 1,550,481