The :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.
The pseudo-class behaves in the same way as the non-standard
By default, Gecko applies a style that creates a red "glow" (using the
box-shadow property) around items, which have the
:moz-ui-invalid pseudo-class applied. See the
:invalid pseudo-class for an example that shows how to override the default style.
|Selectors Level 4
The definition of ':user-invalid' in that specification.
|Working Draft||Adds :user-invalid|
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