v3.26.1
Condensed financial information of the parent company - Condensed statements of cash flows (Details)
 12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2023
CNY (¥)
Cash flows from operating activities:        
Net income/(loss) ¥ 708,627,396 $ 101,332,370 ¥ 91,731,395 ¥ 39,133,539
Adjustments to reconcile net income to net cash used in operating activities:        
Share of loss in subsidiaries, VIEs and VIEs' subsidiaries 18,937,550 2,708,034 4,048,792 (3,207,384)
Share-based compensation expense     2,257,795 4,935,782
Unrealized investment loss/(income) of short-term Investments 6,218,420 889,222 131,604,073 13,502,789
Foreign exchange loss/(gain), net 46,304,828 6,621,502 (20,658,172) 2,931,704
Net cash provided by/(used in) operating activities 687,058,206 98,248,018 (111,000,228) 352,019,561
Net cash provided by (used in) investing activities 845,438,085 120,896,037 (2,344,367,080) 3,895,444,173
Net cash provided by (used in) financing activities 555,594,196 79,448,914 186,843,558 (565,971,561)
Effect of exchange rate changes on cash and cash equivalents (76,554,891) (10,947,204) 46,243,392 12,538,338
Net increase/(decrease) in cash and cash equivalents, and restricted cash and cash equivalents 2,011,535,596 287,645,765 (2,222,280,358) 3,694,030,511
Cash and cash equivalents, and restricted cash and cash equivalents at beginning of the year 5,044,498,144 721,353,640 7,266,778,502 3,572,747,991
Cash and cash equivalents, and restricted cash and cash equivalents at end of the year 7,056,033,740 1,008,999,405 5,044,498,144 7,266,778,502
Parent Company | Reportable legal entity        
Cash flows from operating activities:        
Net income/(loss) 708,627,396 101,332,370 91,731,395 39,133,539
Adjustments to reconcile net income to net cash used in operating activities:        
Share of loss in subsidiaries, VIEs and VIEs' subsidiaries (292,764,592) (41,864,781) 100,160,207 69,628,327
Share-based compensation expense     2,257,795 4,935,782
Unrealized investment loss/(income) of short-term Investments (141,587,920) (20,246,803) 1,925,270 138,739,373
Foreign exchange loss/(gain), net 45,888,491 6,561,967 (20,792,611) 545,948
Payables to employee (5,303,469) (758,386) 4,893,049 405,208
Other payables 1,155,545 165,240 10,942,366 2,935,558
Net cash provided by/(used in) operating activities 316,015,451 45,189,607 191,117,471 256,323,735
Net cash provided by (used in) investing activities 822,761,158 117,653,281 (523,283,656) 29,180,599
Net cash provided by (used in) financing activities 415,494,195 59,414,880 186,843,558 (420,660,054)
Effect of exchange rate changes on cash and cash equivalents (66,679,638) (9,535,061) 37,199,026 (10,899,643)
Net increase/(decrease) in cash and cash equivalents, and restricted cash and cash equivalents 1,487,591,166 212,722,707 (108,123,601) (146,055,363)
Cash and cash equivalents, and restricted cash and cash equivalents at beginning of the year 305,194,205 43,642,191 413,317,806 559,373,169
Cash and cash equivalents, and restricted cash and cash equivalents at end of the year ¥ 1,792,785,371 $ 256,364,898 ¥ 305,194,205 ¥ 413,317,806