v3.26.1
Leases - Summary of information about right of use assets (Detail) - EUR (€)
6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Disclosure Of Leases [Abstract]      
Balance at beginning of period € 756,951 € 813,842 € 813,842
Remeasurement 0   251,427
Depreciation charges (107,162) € (100,000) (229,203)
Impact of transaction of foreign currency 14,487   (79,115)
Balance at end of period € 664,276   € 756,951