import Document , { Html , Head , Main , NextScript } from 'next/document' ; import React from 'react' ; import { ServerStyleSheet } from 'styled-components' ; export default class MyDocument extends Document { static getInitialProps ( { renderPage } ) { const sheet = new ServerStyleSheet ( ) ; const page = renderPage ( ( App ) => ( props ) => sheet . collectStyles ( < App { ... props } / > ) ) ; const styleTags = sheet . getStyleElement ( ) ; return { ... page , styleTags } ; } render ( ) { return ( < Html > < Head > { } { ( this . props as any ) . styleTags } < /Head> < body > < Main /> < NextScript / > < /body> < /Html>); } }