What the standard says
Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible.
Why it matters
Removing the focus ring is the fastest way to make a site unusable by keyboard, and it is still in a lot of CSS resets.
What a failure looks like
- fails`outline: none` with nothing put back.
- failsA focus style so faint it fails 1.4.11.
How to fix it
- doNever remove the outline without replacing it. Style `:focus-visible` instead of deleting `:focus`.
- doGive the indicator at least 3:1 contrast against its surroundings, in both light and dark themes.
How A11ySignal checks it
manual
No automated rule can judge this criterion, and we will not pretend otherwise. A clean scan does not mean 2.4.7 passes — it means nothing we can measure fails. This one needs a person.