The Tooltip component renders in such a way that multiple nested elements are induced. By default, the set styles are passed to the top DOM element of the KendoReact component.
So, in this case, you will need to style the nested elements as it's described in this section: https://www.telerik.com/kendo-react-ui/components/styling/styled-components/#toc-styling-nested-elements.
And here is a sample demo to illustrate the desired result based on the screenshot:
I hope this helps. Let me know if you need any additional information.
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