v3.26.1
Financial investments - Financial investments accounted under trading model (Details) - Wealth management products with no fixed term
12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items]      
Fair value ¥ 88,750,659 $ 12,691,175  
Addition 1,270,936,983 181,741,571 ¥ 97,916,010
Settlements (730,045,659) (104,395,141) (10,417,600)
Total realized gain 1,863,559 266,485 179,600
Fair value change 4,662,583 666,741 1,072,649
Exchange differences (3,500,630) (500,583)  
Fair value ¥ 632,667,495 $ 90,470,248 ¥ 88,750,659