2.4.11 Focus Not Obscured (Minimum)
Conformance level: AA
Criterion released in WCAG version: 2.2
TL;DR: When something gets keyboard focus, it must not be hidden by sticky headers, overlays, or popups. Users need to see the focused element to operate it.
Official description of the success criterion
When a user interface component receives keyboard focus, the component is not entirely hidden due to author-created content.
What to do?
Ensure that when an item gets keyboard focus, it is at least partially visible.
Why is it important?
People who can’t use a mouse need to see what has keyboard focus.
Common pitfalls
Having a modal positioned on the page so that it covers part of the content. If focus handling is not done correctly, it is possible that some interactive element is behind the modal and the focus style of it cannot be seen.
How to test for it?
Check the page and ensure that no element completely covers the interactive elements on the site.