v3.26.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair value measurements - Non-Recurring (Details) - Non-recurring - CNY (¥)
¥ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Property and equipment, Fair Value ¥ 6,788    
Property and equipment, Total Loss for the Year 21,845 ¥ 0 ¥ 0
Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Property and equipment, Fair Value ¥ 6,788