How to include Lumo Styles in a React App??

HI, I am trying to make

It try to make vaadin-grid work in a react app.[omegle]
(https://omegle.onl/) [xender]
(https://xender.vip/) This works somehow, but I fail to style it properly. The Dom Inspector in chrome tells me that inside the vaadin-cell-content the lumo vars are undefined. Any changes I make in the following snippet seem to have no effect.