Basic and diluted net loss per share (Details) - SEK (kr) kr / shares in Units, kr in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Notes and other explanatory information [abstract]
Loss attributable to shareholders	kr (1,721,676)	kr (967,611)
Weighted average number of common shares for basic	43,483,470	40,666,082
Weighted average number of common shares for diluted	43,483,470	40,666,082
Basic net loss per share	kr (39.59)	kr (23.79)
Diluted net loss per share	kr (39.59)	kr (23.79)

The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2025-01-01
-Paragraph 66
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=33&code=ifrs-tx-2025-en-r&anchor=para_66&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2025-01-01
-Paragraph 67
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=33&code=ifrs-tx-2025-en-r&anchor=para_67&doctype=Standard
-URIDate 2025-03-27

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Data Type:	dtr-2022:perShareItemType
Balance Type:	na
Period Type:	duration