v3.26.1
Convertible notes payable (Details)
Jun. 30, 2026
USD ($)
Jun. 30, 2026
CNY (¥)
Dec. 31, 2025
CNY (¥)
Defined Benefit Plan Disclosure [Line Items]      
Convertible notes payable $ (0) ¥ 0 ¥ 0
Investor [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Convertible notes payable $ (0) ¥ (0)