v3.26.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounts receivable, net and Revenue recognition (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenue recognition      
Revenues $ 224,315 $ 255,287 $ 629,428
Return period, subsequent to the receipt of shipment with quality-related issues 12 months    
Provisions for sales return $ 9,104 7,154 15,732
Cost of goods sold 78,439 101,795 269,496
Movements in the allowance for credit losses      
Allowance of credit losses 1,858 1,853  
Credit losses recognized 0 19 0
Revenue included in advance from customers      
Contract liabilities as of January 1 6,625 11,201  
Cash received in advance, net of VAT 190,902 236,087  
Revenue recognized from opening balance of contract liabilities (6,625) (11,201)  
Revenue recognized from contract liabilities arising during current year (181,980) (229,462)  
Contract liabilities as of December 31 $ 8,922 6,625 11,201
Revenue, Remaining Performance Obligation, Optional Exemption, Performance Obligation [true false] true    
Selling and marketing      
Advertising expense $ 96,797 104,347 291,702
General and administrative      
Research and development expense 10,270 15,527 19,105
Chargeback incurred $ 758 681 2,338
Income taxes      
Threshold percentage for not recognizing income tax 50.00%    
Shipping and handling      
Revenue recognition      
Cost of goods sold $ 36,124 48,625 126,628
Membership revenues      
Revenue recognition      
Revenues 220 1,254 $ 1,899
Foreign currency risk | Denominated in RMB      
Foreign currency risk      
Cash and cash equivalents and restricted cash $ 1,046 $ 1,638  
Maximum      
Revenue recognition      
Return period, subsequent to the receipt of shipment with no quality-related issues 7 days    
Return period, subsequent to the receipt of shipment with quality-related issues 30 days