v3.26.1
Financial investments - Summary of investments measured under amortization cost (Details)
12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Investments measured under amortization cost      
Amortized cost, beginning balance ¥ 5,010,417 $ 716,480  
Additions during the year 10,000,000 1,429,981 ¥ 5,000,000
Maturities during the year (10,062,632) (1,438,937)  
Interest earned during the year 52,215 7,467  
Interest accrued during the year 9,792 1,400 10,417
Amortized cost, ending balance ¥ 5,009,792 $ 716,391 ¥ 5,010,417