Customize the UI appearance of the control

@Html.EJS().NumericTextBox("numeric").Value(10).Placeholder("numeric").FloatLabelType(Syncfusion.EJ2.Inputs.FloatLabelType.Auto).CssClass("e-style").Render()
<style>
    .e-numeric.e-style .e-control.e-numerictextbox {
        color: royalblue;
        font-size: xx-large;
        border: 0px;
    }

    .e-input-group.e-control-wrapper:not(.e-success):not(.e-warning):not(.e-error):not(.e-float-icon-left), .e-float-input.e-control-wrapper:hover:not(.e-success):not(.e-warning):not(.e-error):not(.e-disabled):not(.e-float-icon-left) {
        border-color: royalblue;
    }

    .e-control-wrapper.e-numeric.e-float-input.e-style .e-spin-down {
        color: royalblue;
    }

    .e-control-wrapper.e-numeric.e-float-input.e-style .e-float-line::before {
        background: royalblue;
    }

    .e-control-wrapper.e-numeric.e-float-input.e-style .e-float-line::after {
        background: royalblue;
    }

    .e-control-wrapper.e-numeric.e-float-input.e-style .e-spin-up {
        color: royalblue;
    }

    .e-control-wrapper.e-numeric.e-float-input.e-style.e-input-group .e-float-text.e-label-top {
        color: royalblue;
        font-size: medium;
    }
</style>

public ActionResult customCss()
{
    return View();
}