Intangible assets (Details) - HKD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Disclosure of detailed information about intangible assets [line items] | ||
| Beginning balance | $ 825,000 | |
| Ending balance | 780,000 | $ 825,000 |
| Patent license | ||
| Disclosure of detailed information about intangible assets [line items] | ||
| Beginning balance | 825,000 | |
| Ending balance | $ 780,000 | 825,000 |
| Estimated useful lives | 20 years | |
| Cost | Patent license | ||
| Disclosure of detailed information about intangible assets [line items] | ||
| Beginning balance | $ 900,000 | 900,000 |
| Ending balance | 900,000 | 900,000 |
| Amortization | Patent license | ||
| Disclosure of detailed information about intangible assets [line items] | ||
| Beginning balance | (75,000) | (30,000) |
| Charge for the year | 45,000 | 45,000 |
| Ending balance | $ (120,000) | $ (75,000) |