v3.26.1
Short term investments (Details 1)
Jun. 30, 2026
USD ($)
Jun. 30, 2026
CNY (¥)
Dec. 31, 2025
CNY (¥)
Defined Benefit Plan Disclosure [Line Items]      
Marketable securities $ 127,404,355 ¥ 867,738,320 ¥ 1,138,090,600
Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Marketable securities   867,738,320 1,138,090,600
Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Marketable securities  
Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Marketable securities