v3.26.1
Summary of significant accounting policies - Schedule of quoted market prices to determine the fair value of an asset or liability (Details) - CNY (¥)
Dec. 31, 2025
Dec. 31, 2024
Summary of significant accounting policies    
Investment in equity investees ¥ 11,062,659 ¥ 76,929,667
Fair value recurring    
Summary of significant accounting policies    
Investment in equity investees 11,062,659 76,929,667
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value recurring    
Summary of significant accounting policies    
Investment in equity investees ¥ 11,062,659 ¥ 76,929,667