$ npm i styled-components
$ npm i styled-reset
// src/style/GlobalStyles.js
import { createGlobalStyle } from "styled-components";
import reset from "styled-reset";
const GlobalStyles = createGlobalStyle`
${reset}
`;
export default GlobalStyles;
// src/App.js
import GlobalStyles from "./style/GlobalStyles";
const App = () => (<><GlobalStyles />...</>)