Download the example or clone the repo:
curl https://codeload.github.com/zeit/next.js/tar.gz/master | tar -xz --strip=2 next.js-master/examples/head-elements
cd head-elementsInstall it and run:
npm install
npm run devDeploy it to the cloud with now (download)
nowFor every page you can inject elements into the page head. This way you can add stylesheets, JS scripts, meta tags, a custom title or whatever you think is convenient to add inside the <head> of your page.
This example shows in pages/index.js how to add a title and a couple of meta tags.