v3.26.1
INCOME TAXES - Reconciliation between the Effective and Statutory Income 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 (¥)
Effective income tax rate reconciliation, Amount        
Net income before income tax ¥ 466,715   ¥ (101,246) ¥ (475,310)
Statutory income tax rate 116,679      
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent     (17.37%) (12.42%)
Effect of cross-border tax laws 27,517      
Share-based compensation 28,663      
Other items 467      
Effect of super deduction on R&D expenses (83,973)      
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent     (0.38%) (0.32%)
Effect of 15% preferential tax rate as an HNTE ¥ (50,776)      
Tax Jurisdiction of Domicile [Extensible Enumeration] Chinese Mainland Chinese Mainland    
Income tax expenses ¥ 30,835 $ 4,409 ¥ 1,130 ¥ 658
Effective income tax rate reconciliation, Percent        
Percentage of net income 100.00% 100.00%    
Statutory income tax rate 25.00% 25.00% 25.00% 25.00%
Statutory tax rate difference between foreign country and PRC     8.00% (0.79%)
Changes in valuation allowance     (122.79%) (49.46%)
Effect of cross-border tax laws 5.90% 5.90%    
Share-based compensation 6.14% 6.14%    
Other items 0.10% 0.10%    
Effect of super deduction on R&D expenses (17.99%) (17.99%) 105.66% 37.21%
Tax-free income     (0.38%) (0.32%)
Effect of 15% preferential tax rate as an HNTE (10.88%) (10.88%)    
Income tax expenses 6.61% 6.61% (1.12%) (0.14%)
Chinese Mainland        
Effective income tax rate reconciliation, Amount        
Changes in valuation allowance ¥ 44,224      
Effective income tax rate reconciliation, Percent        
Changes in valuation allowance 9.48% 9.48%    
Cayman        
Effective income tax rate reconciliation, Amount        
Statutory tax rate difference between foreign country and PRC ¥ (29,058)      
Effective income tax rate reconciliation, Percent        
Statutory tax rate difference between foreign country and PRC (6.23%) (6.23%)    
The British Virgin Islands        
Effective income tax rate reconciliation, Amount        
Statutory tax rate difference between foreign country and PRC ¥ (43,662)      
Effective income tax rate reconciliation, Percent        
Statutory tax rate difference between foreign country and PRC (9.36%) (9.36%)    
United States        
Effective income tax rate reconciliation, Amount        
Statutory tax rate difference between foreign country and PRC ¥ (931)      
Changes in valuation allowance ¥ 7,801      
Effective income tax rate reconciliation, Percent        
Statutory tax rate difference between foreign country and PRC (0.20%) (0.20%)    
Changes in valuation allowance 1.67% 1.67%    
Other foreign jurisdictions        
Effective income tax rate reconciliation, Amount        
Other foreign jurisdictions ¥ 13,884      
Effective income tax rate reconciliation, Percent        
Other foreign jurisdictions 2.98% 2.98%