title: Unknown pseudo-element or pseudo-class :focus-within
body: <p>i am getting this error in w3 validations is there any way to solve it i tried many ways but not able to resolve it.<a href="https://i.stack.imgur.com/4rQQt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4rQQt.png" alt="enter image description here"></a></p>