css/selectors/focus-within-006.html

<!DOCTYPE html>
<html lang=en class="reftest-wait">
<meta charset="utf-8">
<title>Selectors Level 4: focus-within</title>
<link rel="author" title="Keyong Li" href="mailto:kli79@bloomberg.net">
<link rel="author" title="Florian Rivoal" href="mailto:florian@rivoal.net">
<link rel="help" href="https://drafts.csswg.org/selectors-4/#focus-within-pseudo">
<link rel="match" href="focus-within-006-ref.html">
<meta name="assert" content="Test that :focus-within works on form controls, using an input element.">
<style>
:focus {
  outline: none;

  /* Make the caret invisible
     since it matches the color of the text, which is transparent,
     while keeping the text readable thanks to its shadow.
     Not using the caret-color property as it is too new to be relied on. */
  color: transparent; text-shadow: black 0px 0px 0px;
}

/* Use blue to indicate that the user needs to pay attention.
   This element needs to be focused for the test to make sense. */
#focusme:not(:focus) {
  border: solid 15px blue;
}

#focusme:focus:not(:focus-within) {
  background: red;
}
div:focus-within {
  border: solid 5px green;
}
</style>
<p>Test passes if, when the element below is focused,
it is surrounded by a thick green border.
There must be no red or blue once it is focused.</p>
<div>
  <div>
    <div>
      <input id="focusme" value="Focus this element">
    </div>
  </div>
</div>
<script>
var focusme = document.getElementById('focusme');
focusme.focus();
document.documentElement.classList.remove('reftest-wait');
</script>
</html>