Focus Not Obscured (Enhanced)
When a UI component receives keyboard focus, no part of the focused component is hidden by author-created content.
What it requires
WCAG 2.2 SC 2.4.12 (AAA) goes beyond the AA version (2.4.11). 2.4.11 allows partial obscuring as long as some part of the focused component remains visible. 2.4.12 requires the entire focused component to be unobscured.
The most-common failure: a sticky cookie banner or sticky chat widget that overlaps a focused form field below it. AA passes if any part of the focused field shows; AAA fails unless the field is entirely visible.
Common Shopify failure
Sticky chat widget bottom-right that fully covers an "Apply discount" link when the link receives keyboard focus.
How to fix it
Reserve scroll-padding-bottom equal to the chat widget height, or auto-collapse the widget when a form field nearby receives focus.
Primary source: W3C — WCAG 2.2 Understanding 2.4.12