Example of integration Bootstrap 4 and Next.js
Usage:
git clone https://github.com/frostspb/bootsrap_nextjs_example.git
cd bootsrap_nextjs_example
npm install
npm run dev
Pay attention to the files:
next.config.js - contains config of CSS Loader
_document.js - contains compiled styles
and the line
"import 'bootstrap/dist/css/bootstrap.min.css';"
in layouts/main.js