v3.26.1
Summary of significant accounting policies (Details Narrative)
6 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2026
CNY (¥)
Dec. 31, 2025
CNY (¥)
Accounting Policies [Abstract]      
Foreign cuurency transactions USD 1.00 to RMB 6.8109 and RMB 7.0288    
Foreign cuurency transactions USD 1.00 to RMB 6.8956 and RMB 7.1837    
Doubtful accounts for accounts receivable $ 467,358 ¥ 3,183,129 ¥ 5,513,270
Contract assets   0 0
Contract liabilities $ 617,339 ¥ 4,204,635 ¥ 5,483,268