Creating styles

In notebook:
Building Modern Web Apps
Created at:
css Webpack libraries
Live reloading styles

webpack can include css, images, etc.

creates a dir called styles 

then in his app.js : ​import styles from './styles/main/css​ 
webpack handles all the resources and also does the live reloading (in development mode)
We didn't have to set up the watcher, just follows the require paths.
Works with any browser (mobile, desktop)

The live reload doesn't work with the main entry point (app.js in his case)
You can use import or require. (you can require without assigning it to a local variable, as opposed to ES6 imports).

Build step

shows auto css prefixing (for css transforms) 
uses postcss autoprefixing tool

Just by file extensions webpack will understand how to process your file. SASS files out of the box.

The dev server puts everything in the app.js (even css) the build process will output proper css files with versioned names, etc.