 with TalkBack) or black (on iOS with VoiceOver)
rectangle shown on screen to indicate what element an accessibility
user is currently interacting with.</p>
<p>The accessibility focus is different from the input focus. The input focus
is usually held by the element that currently responds to keyboard inputs.
Accessibility focus and input focus can be held by two different nodes!</p>
        </section>
                <section class="summary source-code" id="source">
          <h2><span>Implementation</span>