Income tax (Schedule of effect of tax holiday) (Details) - CNY (¥) ¥ / shares in Units, ¥ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income tax
Tax saving amount due to preferential tax rates	¥ 10,740	¥ 10,132	¥ 1,993
Income per share effect-basic (in CNY per share)	¥ 0.06	¥ 0.06	¥ 0.01
Income per share effect-diluted (in CNY per share)	¥ 0.06	¥ 0.06	¥ 0.01

Diluted per share amount effect of the income tax benefit resulting from the income tax holidays granted by taxing jurisdictions

No definition available.

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- References

No definition available.

+ Details

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- Definition

The amount of income taxes from which a reporting entity is exempt or for which it will receive a reduction in income taxes as a result of the income tax holiday granted by the taxing jurisdiction.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-2

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- Definition

Per share amount effect of the income tax benefit resulting from the income tax holidays granted by taxing jurisdictions.

+ References

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