v3.25.1
Income taxes - Schedule of effective tax rate (Details)
12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Income taxes      
U.S. Statutory rates 21.00% 21.00% 21.00%
Foreign income not recognized in USA (21.00%) (21.00%) (21.00%)
China income taxes (including Hong Kong SAR) 5.10% 7.70% 4.10%
Australia income taxes 0.10% 0.20% (0.60%)
Impact of tax rate in other jurisdictions (15.80%) (2.10%) (1.30%)
Impact of tax reduction of Hong Kong profits tax     0.10%
Tax effect of non-deductible expenses 11.10% 1.60% (0.40%)
Valuation allowance (0.70%)   4.20%
Under provision in respect of prior years   0.10% (1.60%)
Other     0.10%
Effective income taxes 0.20% 7.50% 4.60%