12.3. Ensure that keyboard focus is visible
In order to ensure that users navigating using the keyboard know where they are on the page, each interactive element (links, buttons, form fields, etc.) must stand out visually when it receives focus.
Note
Ensure that this focus indicator has sufficient contrast.
Tip
Good accessibility practice is to systematically back up each :hover rule with a :focus rule in CSS.
For example:
main a:hover,
main a:focus {
text-decoration: none;
}