We_Relese/App/Relese/Views/Shared/Modals/_Modal.cshtml

@model WeApp.Views.Shared.Modals.ModalViewModel
@{
    string width = Model.Width == null || Model.Width <= 500 ? "" : "max-width:" + Model.Width + "px";
    string size = string.IsNullOrEmpty(Model.SizeClass) ? "" : "modal-" + Model.SizeClass;
}
<!-- MODAL  @(Model.ModalId)  START-->
<section>
    <div class="modal fade" id="@Model.ModalId" tabindex="-1">
        <div class="modal-dialog @(size)" style="@width">
            <div class="modal-content">
                @Html.Partial("Modals/_ModalHeader", Model.Header)
                @if (Model.Body != null)
                {
                    @Html.Partial("Modals/_ModalBody", Model.Body)
                }
                @Html.Partial("Modals/_ModalFooter", Model.Footer)
            </div>
        </div>
    </div>
</section>
<!-- MODAL  @(Model.ModalId)  END-->