Scrollable regions must be keyboard focusable

Checks scrollable containers for keyboard focusability and accessible naming when needed.

• Keyboard-only users may be blocked from reading hidden content
• Screen magnifier users often rely on keyboard scrolling
• Inaccessible scroll areas hide critical information

Make custom scroll regions focusable and provide visible focus styling.

Bad Example:

<div class="scroll-panel" style="overflow:auto; max-height:200px;">...</div>

Good Example:

<div
  class="scroll-panel"
  style="overflow:auto; max-height:200px;"
  tabindex="0"
  aria-label="Order history"
>
  ...
</div>

• Using overflow containers without tabindex
• Removing focus outlines via CSS
• Hiding content inside keyboard-inaccessible panels

• Navigate with Tab and confirm scroll panel receives focus
• Use arrow/PageUp/PageDown keys to scroll focused region
• Verify visible focus indicator is present