aspnet-client-validation/dist/aspnet-validation.css

Enables ASP.NET MVC client-side validation, without jQuery!

.field-validation-error {
    color: red;
    font-style: italic;
}

.input-validation-error {
    border-color: red;
    outline-color: red;
}

.input-validation-valid {
    border-color: green;
    outline-color: green;
}

.validation-summary-errors {
    color: red;
    font-style: italic;
}

.validation-summary-valid span {
    display: none;
}