v3.26.1
Share-based compensation - Summary of Share Option Activity (Details) - CNY (¥)
¥ / shares in Units, ¥ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Share-based compensation.    
Number of Options, Outstanding, Beginning Balance 8,794,368  
Number of Options, Granted 522,066  
Number of Options, Expired 40,227  
Number of Options, Exercised 970,693  
Number of Options, Outstanding, Ending Balance 8,305,514 8,794,368
Number of Options, Vested and expected to vest 8,305,514  
Number of Options, Vested 8,083,840  
Weighted-Average Exercise Price, Outstanding, Beginning Balance ¥ 8.65  
Weighted-Average Exercise Price, Expired 16.08  
Weighted-Average Exercise Price, Exercised 3.07  
Weighted-Average Exercise Price, Outstanding, Ending Balance 8.72 ¥ 8.65
Weighted-Average Exercise Price, Vested and expected to vest 8.72  
Weighted-Average Exercise Price, Vested 9.21  
Weighted-Average grant-date Fair Value per Option, Outstanding, Beginning Balance 12.58  
Weighted-Average grant-date Fair Value per Option, Granted 3.62  
Weighted-Average grant-date Fair Value per Option, Expired 20.23  
Weighted-Average grant-date Fair Value per Option, Exercised 5.59  
Weighted-Average grant-date Fair Value per Option, Outstanding, Ending Balance 12.8 ¥ 12.58
Weighted-Average grant-date Fair Value per Option, Vested and expected to vest 12.8  
Weighted-Average grant-date Fair Value per Option, Vested ¥ 13.47  
Weighted Average Remaining Contractual Term (Years), Outstanding 4 years 8 months 1 day 5 years 4 months 20 days
Weighted Average Remaining Contractual Term (Years), Vested and expected to vest 4 years 8 months 1 day  
Weighted Average Remaining Contractual Term (Years), Vested 4 years 7 months 13 days  
Aggregate Intrinsic Value, Outstanding ¥ 11,738 ¥ 12,923
Aggregate Intrinsic Value, Vested and expected to vest 11,738  
Aggregate Intrinsic Value, Vested ¥ 11,006