How to add css class to textblock?

how to add css class to textblock?, 'cause i need to apply styles depends upon my project theme.

              row: 0, alignment: go.Spot.Center,
              textAlign: 'center',
              margin: new go.Margin(0, 15, 0, 8),  // leave room for Button
              isMultiline: false,
              stroke: "#FCFCFC",
              editable: true,
              minSize: new go.Size(150, NaN),
              textValidation: entityNameValidation,
              textEdited: updateEntityName
            new go.Binding("text", "key"))```

You can set or bind the properties of TextBlock:

Perhaps you want to use

Hello kumar1,I want to add -webkit-text-shadow or text-shadow CSS to textBlock.Can you tell me how to code?Thanks a lot!