Share-based compensation - Unregistered Securities (Details) - Plan - USD ($) |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
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| Share-based compensation | |||
| Granted | 741,500 | 109,853 | |
| Exercise price | $ 2.657 | $ 4.711 | |
| Remaining contractual term | 9 years 4 months 13 days | 9 years 7 months 20 days | |
| Intrinsic value of options outstanding | $ 7,392 | ||
| Non-qualified stock options | |||
| Share-based compensation | |||
| Granted | 11,700 | ||
| Options term | 10 years | ||
| Exercise price | $ 250 | ||
| Vesting percentage | 100.00% | ||
| Remaining contractual term | 4 years 5 months 19 days | ||
| Unrecognized compensation expense | $ 0 | ||
| Intrinsic value of options outstanding | $ 0 | ||
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- Definition Amount of cost not yet recognized for nonvested award under share-based payment arrangement. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Gross number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Percentage of vesting of award under share-based payment arrangement. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Period from grant to expiration date of share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Weighted-average contractual term remaining for option award outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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