Selector pseudo-class :focus-within

The :focus-within CSS pseudo-class matches an
element if the element or any of its descendants
are focused. In other words, it represents an
element that is itself matched by the :focus
pseudo-class or has a descendant that is matched
by :focus

label:focus-within {
  font-weight: bold;
}

form:focus-within {
  background: #ff8;
  color: black;
}