v3.26.1
SHARE-BASED COMPENSATION - Restricted share units ("RSUs") (Details) - CNY (¥)
¥ / shares in Units, ¥ in Thousands
12 Months Ended
Nov. 12, 2025
Aug. 29, 2025
Apr. 22, 2025
Mar. 10, 2025
Feb. 07, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Weighted-Average Grant Date Fair Value Per Share                
Compensation expenses to options granted           ¥ 114,652 ¥ 116,064 ¥ 234,624
Unrecognized share-based compensation expense           ¥ 239,216    
Unrecognized stock compensation expense, expected to be recognized over a weighted-average period           2 years 10 months 9 days    
Restricted share units ("RSUs")                
Numbers of RSUs                
Outstanding at the beginning           550,347    
Number of awards granted 338,340 338,340 338,340 338,340 338,340 338,340    
Forfeited           58,524    
Vested           158,550    
Outstanding at the end           671,613 550,347  
Weighted-Average Grant Date Fair Value Per Share                
Outstanding at the beginning (in dollars per share)           ¥ 38.25    
Granted (in dollars per share)           149.68 ¥ 31.22 ¥ 76.52
Forfeited (in dollars per share)           62.31    
Exercised (in dollars per share)           45.22    
Outstanding at the end (in dollars per share)           ¥ 90.65 ¥ 38.25  
Total intrinsic value of share units exercised           ¥ 17,028 ¥ 7,789 ¥ 2,252
Compensation expenses to options granted           8,200 ¥ 6,673 ¥ 5,646
Unrecognized share-based compensation expense           ¥ 56,173    
Unrecognized stock compensation expense, expected to be recognized over a weighted-average period           3 years 6 months 10 days    
Restricted share units ("RSUs") | Vested on each of the first and second anniversaries                
Share-Based Compensation Arrangement by Share-Based Payment Award                
Vesting percentage           50.00%    
Numbers of RSUs                
Number of awards granted           17,858    
Restricted share units ("RSUs") | Vested on each of the first, second, third and fourth anniversaries                
Share-Based Compensation Arrangement by Share-Based Payment Award                
Vesting percentage           25.00%    
Numbers of RSUs                
Number of awards granted           310,115    
Restricted share units ("RSUs") | Vest every six months                
Share-Based Compensation Arrangement by Share-Based Payment Award                
Vesting percentage           12.50%    
Numbers of RSUs                
Number of awards granted           3,251    
Restricted share units ("RSUs") | Vested on each of the first anniversary                
Share-Based Compensation Arrangement by Share-Based Payment Award                
Vesting percentage           33.33%    
Numbers of RSUs                
Number of awards granted           7,116