next.js/examples/with-react-with-styles/withStyles.js

import ThemedStyleSheet from 'react-with-styles/lib/ThemedStyleSheet'
import aphroditeInterface from 'react-with-styles-interface-aphrodite'
import { css, withStyles, ThemeProvider } from 'react-with-styles'
import MyDefaultTheme from './defaultTheme'

ThemedStyleSheet.registerDefaultTheme(MyDefaultTheme)
ThemedStyleSheet.registerInterface(aphroditeInterface)

export { css, withStyles, ThemeProvider, ThemedStyleSheet }