Retirement benefits obligations - Balance sheet (Details) - CHF (SFr)	6 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Defined benefit plans
Net defined benefit (liability) asset	SFr (184,847)	SFr (371,608)
Increase (decrease) in retirement benefit obligation	(200,000)
Defined benefit obligation
Defined benefit plans
Net defined benefit (liability) asset	(5,096,588)	(5,126,017)
Fair value of plan assets
Defined benefit plans
Net defined benefit (liability) asset	SFr 4,911,741	SFr 4,754,409

The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2025-01-01
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-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 206
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_206_a&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 206
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_206_a&doctype=Standard
-URIDate 2025-03-27

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