css-loader : Unexpected token of css coming from node module

I will explain my issue with the Github issue style :

What is the current behavior?

Cannot load css. The full error message:

If the current behavior is a bug, please provide the steps to reproduce.
My package.json : https://gist.github.com/jy95/99377c113252e6baaa23087abe859814
My webpack.config.js : https://gist.github.com/jy95/16b0f03d46b087c6f2640c8e9178914f

Please mention other relevant information such as the browser version, Node.js version, webpack version and Operating System.
Node : 6.10.3
OS: Windows 10

PS: Before you can tell me to see with ExtractTextPlugin, I would like an explanation why I got this error (I also tried to required the css in my entry : app.js , same result )

via jacques y