Orders ship within two business days.
The test is not whether the attributes exist. The test is whether the interface tells one coherent story:
The control has native button semantics and a useful name.
aria-controls resolves to the real panel ID.
aria-expanded changes from false to true .
The panel's actual visibility changes with that state.
Mouse, Enter, and Space activation work as expected.
Do not turn that into the claim that all collapsed content is invisible to all agents. Content can remain in the DOM, be excluded from the current AX state, be injected after a request, or become available after interaction. Test the exact implementation.
For product facts, eligibility requirements, pricing conditions, and an article's core answer, I would not make a successful optional interaction the only discovery path. Render essential decision content and use disclosures for added depth. That is a risk-control recommendation, not a universal rule against hidden panels.
Validate Hierarchy, Landmarks, and Fake Links
A page built from anonymous containers gives the browser less structure to work with. Start with one primary