Override CSS ValidationMessageFor

我似乎无法在Ajax表单的validationMessageFor中放入新的css…

 @using (Ajax.BeginForm(new AjaxOptions { HttpMethod = "POST", OnSuccess = "Success", OnFailure = "Fail" }))
{
<div class="separaror">
    <div class="line1">
        @Html.LabelFor(m => m.Name)
        <br />
        @Html.TextBoxFor(m => m.Name)
            @Html.ValidationMessageFor(m => m.Name)
    </div>
    <div class="linha2">
        <br>
        <input type="submit" value="Save" />
        <input type="button" id="btnCancel" value="Cancel" />
    </div>
</div>

}

我的css

.field-validation-error {
color: #e80c4d;
font-weight: bold;
}
.field-validation-valid {
display: none;
}
input.input-validation-error {
border: 1px solid #e80c4d;
}
input[type="checkbox"].input-validation-error {
border: 0 none;
}
.validation-summary-errors {
color: #e80c4d;
font-weight: bold;
font-size: 1.1em;
}
.validation-summary-valid {
display: none;
}

它不会覆盖。。为什么？任何帮助都将不胜感激！我直接从visual studio的默认Asp MVC 4应用程序中复制了css，我不知道为什么这不起作用。我正在做的应用程序不是mvc 4中的默认应用程序，所以我一定缺少