anvil/striker-ui/pages/_document.tsx

import Document, { DocumentContext, DocumentInitialProps } from 'next/document';
import { ServerStyleSheet } from 'styled-components';

class StyledDocument extends Document {
  static async getInitialProps(
    context: DocumentContext,
  ): Promise<DocumentInitialProps> {
    const styleSheet = new ServerStyleSheet();
    const originalRenderPage = context.renderPage;

    try {
      context.renderPage = () =>
        originalRenderPage({
          enhanceApp: (App) => (props) =>
            // eslint-disable-next-line react/jsx-props-no-spreading
            styleSheet.collectStyles(<App {...props} />),
        });

      const initialProps = await Document.getInitialProps(context);

      return {
        ...initialProps,
        styles: (
          <>
            {initialProps.styles}
            {styleSheet.getStyleElement()}
          </>
        ),
      };
    } finally {
      styleSheet.seal();
    }
  }
}

export default StyledDocument;