how to give border and border-radius to stacklayout in nativescript

I'm new to nativescript.I don't know how to give border and border-radius to stacklayout.

Below I have posted what I tried so far:

component.html:

 <StackLayout class ="stackBorder" orientation="horizontal">
    <Label text="Label 1" width="50" height="50" > </Label>
    <Label text="Label 2" width="50" height="50" > </Label>
    <Label text="Label 3" width="50" height="50" backgroundColor="white"> </Label>
    <Label text="Label 4" width="50" height="50" backgroundColor="white"> </Label>
  </StackLayout>

component.css:

StackLayout {
  margin: 10;
  background-color: green;

}

.stackBorder {
 border: 2px solid red;
   border-radius: 8px;
}

component.ts:

@Component({
    selector: "sdk-child-component",
    moduleId: module.id,
    templateUrl: "./component.html",
    styleUrls: ["./component.css"]
})

Finally I'm unable to see the border in stacklayout.