v3.26.1
Income tax (Reconciliation of Statutory tax rate to Effective tax rate) (Details)
¥ in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2023
CNY (¥)
Amount        
PRC Statutory tax rate ¥ (50,191)      
Changes in valuation allowances 37,086      
Return to provision adjustments 5,381      
Withholding tax 3,534      
Total provision for income taxes ¥ 9,907 $ 1,417 ¥ 20,739 ¥ 12,003
Tax Jurisdiction of Domicile [Extensible Enumeration] China China    
Percent        
Statutory income tax rate 25.00% 25.00% 25.00% 25.00%
Non-deductible share-based compensation     (20.50%) (11.92%)
Foreign tax effects/Statutory tax rate difference     (31.87%) (4.79%)
Effect of preferential tax rate     (11.75%) 0.92%
Changes in valuation allowance     (2.78%) (25.65%)
HK tax-free interest income     6.56% 3.51%
Research and development super deduction     13.04% 7.40%
Changes in valuation allowance and others (18.50%) (18.50%)    
Return to provision adjustments (2.70%) (2.70%)    
Withholding tax (1.80%) (1.80%)    
Effective income tax rate (4.90%) (4.90%) (22.30%) (5.53%)
China        
Amount        
Others ¥ 22      
Research and development super deduction (10,177)      
Nontaxable or nondeductible items 8,581      
Effect of preferential tax benefit ¥ (10,740)      
Percent        
Others 0.20% 0.20%    
Research and development super deduction 5.10% 5.10%    
Non taxable or nondeductible items (4.30%) (4.30%)    
Effect of preferential tax benefit 5.30% 5.30%    
Hong Kong        
Amount        
Foreign tax effects/Statutory tax rate difference ¥ 2,757      
Changes in valuation allowances 2,683      
Nondeductible impairment loss of goodwill 3,036      
Others ¥ (1,300)      
Percent        
Foreign tax effects/Statutory tax rate difference (1.40%) (1.40%)    
Changes in valuation allowance (1.30%) (1.30%)    
Nondeductible impairment loss of goodwill (1.40%) (1.40%)    
Others 0.60% 0.60%    
Singapore        
Amount        
Foreign tax effects/Statutory tax rate difference ¥ 4,938      
Changes in valuation allowances 9,785      
Others ¥ 714      
Percent        
Foreign tax effects/Statutory tax rate difference (2.50%) (2.50%)    
Changes in valuation allowance (4.90%) (4.90%)    
Others (0.40%) (0.40%)    
Other Foreign Jurisdictions        
Amount        
Others ¥ 3,798      
Percent        
Others (1.90%) (1.90%)