cssnext-loader 
a webpack loader for cssnext
install
$ npm install cssnext-loader
api
cssnext
in your webpack.config.js
module.exports = {
entry: "path/to/entry",
output: {
path: "path/to/output/",
filename: "bundle.js"
},
cssnext : {
features : {
import : {
path : ["src/assets/stylesheets"]
}
}
}
}
in your js file :
var css = require("style-loader!css-loader!../..!./file.css")
you can also configure webpack so that it always parses CSS files like this :
module: {
loaders: [
{
test: /\.css$/,
loader: "style-loader!css-loader!cssnext-loader"
}
]
}