visually-hidden-focusable can also be used as mixins.
visually-hidden to hide an element, but while still allowing it to be exposed to assistive technologies (such as screen readers)
Title for screen readers
<h2 class="visually-hidden">Title for screen readers</h2>
.visually-hidden-focusable to visually hide an element by default, but to display it when it’s focused (e.g. by a keyboard-only user).
.visually-hidden-focusable can also be applied to a container–thanks to
:focus-within, the container will be displayed when any child element of the container receives focus.
<a class="visually-hidden-focusable" href="#content">Skip to main content</a> <div class="visually-hidden-focusable">A container with a <a href="#">focusable element</a>.</div>