Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
:user-invalid CSS pseudo-class represents any validated form element whose value isn't valid based on their validation constraints, after the user has interacted with it.
:user-invalid pseudo-class must match an
:out-of-range, or blank-but
:required element between the time the user has attempted to submit the form and before the user has interacted again with the form element.
Note: The pseudo-class behaves in the same way as the non-standard