v3.26.1
Condensed financial information of the parent company - Condensed balance sheets (Details)
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2023
CNY (¥)
Current assets:        
Cash and cash equivalents ¥ 5,532,375,615 $ 791,119,191 ¥ 4,263,311,636 ¥ 7,207,343,478
Short-term investments 879,224,792 125,727,473 1,118,547,455  
Time and Structured deposits 1,885,242,800 269,586,135 2,009,018,598  
Other current assets 1,453,174,071 207,801,128 1,933,182,792  
Total current assets 11,392,218,043 1,629,065,513 10,139,522,498  
Non-current assets:        
Total non-current assets 2,220,692,744 317,554,840 2,324,704,787  
TOTAL ASSETS 13,612,910,787 1,946,620,353 12,464,227,285  
Current liabilities:        
Short-term borrowings 1,576,000,000 225,365,003 720,000,000  
Total current liabilities 1,980,651,826 283,229,445 1,124,092,207  
Total non-current liabilities 655,070 93,674 48,706,048  
Total liabilities 1,981,306,896 283,323,119 1,172,798,255  
Shareholders' equity        
Treasury shares (1,716,516,330) (245,458,571) (1,419,285,878) ¥ (899,627,520)
Additional paid-in capital 4,024,378,922 575,478,532 4,026,668,369  
Accumulated other comprehensive income/ (loss) (55,181,141) (7,890,798) 13,751,495  
Retained earnings 9,378,746,552 1,341,142,920 8,670,119,156  
Total equity 11,631,603,891 1,663,297,234 11,291,429,030  
TOTAL LIABILITIES AND EQUITY 13,612,910,787 1,946,620,353 12,464,227,285  
Class A Ordinary shares        
Shareholders' equity        
Common stock 132,052 18,883 132,052  
Class B Ordinary shares        
Shareholders' equity        
Common stock 43,836 6,268 43,836  
Parent Company | Reportable legal entity        
Current assets:        
Cash and cash equivalents 1,792,785,371 256,364,898 305,194,205  
Short-term investments 574,322,435 82,127,016 698,152,621  
Time and Structured deposits     380,047,326  
Short-term amounts due from related parties ¥ 320,663,822 $ 45,854,317 ¥ 440,259,744  
Other Receivable, after Allowance for Credit Loss, Current, Related Party, Type [Extensible Enumeration] Related Party [Member] Related Party [Member] Related Party [Member]  
Other current assets ¥ 42,098 $ 6,020 ¥ 14,670  
Total current assets 2,687,813,726 384,352,251 1,823,668,566  
Non-current assets:        
Investments in subsidiaries, VIEs and VIEs' subsidiaries 10,483,508,886 1,499,121,832 10,211,096,821  
Total non-current assets 10,483,508,886 1,499,121,832 10,211,096,821  
TOTAL ASSETS 13,171,322,612 1,883,474,083 12,034,765,387  
Current liabilities:        
Short-term borrowings 1,436,000,000 205,345,269 720,000,000  
Accrued expenses and other inter-companies 12,424,971 1,776,747 19,456,357  
Short-term amounts due to related parties ¥ 91,293,750 $ 13,054,833 ¥ 3,880,000  
Other Liability, Current, Related Party, Type [Extensible Enumeration] Related Party [Member] Related Party [Member] Related Party [Member]  
Total current liabilities ¥ 1,539,718,721 $ 220,176,849 ¥ 743,336,357  
Total liabilities 1,539,718,721 220,176,849 743,336,357  
Shareholders' equity        
Treasury shares (1,716,516,330) (245,458,571) (1,419,285,878)  
Additional paid-in capital 4,024,378,922 575,478,532 4,026,668,369  
Accumulated other comprehensive income/ (loss) (55,181,141) (7,890,798) 13,751,495  
Retained earnings 9,378,746,552 1,341,142,920 8,670,119,156  
Total equity 11,631,603,891 1,663,297,234 11,291,429,030  
TOTAL LIABILITIES AND EQUITY 13,171,322,612 1,883,474,083 12,034,765,387  
Parent Company | Reportable legal entity | Class A Ordinary shares        
Shareholders' equity        
Common stock 132,052 18,883 132,052  
Parent Company | Reportable legal entity | Class B Ordinary shares        
Shareholders' equity        
Common stock ¥ 43,836 $ 6,268 ¥ 43,836