v3.26.1
PROPERTY, PLANT AND EQUIPMENT, NET - Depreciation expense (Details) - CNY (¥)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
PROPERTY, PLANT AND EQUIPMENT, NET.      
Depreciation expense ¥ 110,693,354 ¥ 121,880,535 ¥ 147,507,340
Cost of revenues      
PROPERTY, PLANT AND EQUIPMENT, NET.      
Depreciation expense 38,373,759 32,342,412 26,811,275
Selling and marketing expenses      
PROPERTY, PLANT AND EQUIPMENT, NET.      
Depreciation expense 62,465,700 78,589,848 107,996,726
Research and development expenses      
PROPERTY, PLANT AND EQUIPMENT, NET.      
Depreciation expense 3,982,199 3,847,241 3,641,514
General and administrative expenses      
PROPERTY, PLANT AND EQUIPMENT, NET.      
Depreciation expense ¥ 5,871,696 ¥ 7,101,034 ¥ 9,057,825