Compile assets but not concatenate them

Ember CLI
1

What is needed to compile some SCSS and minifies it, but not concat in a single vendor.css or application-name.css?

2

This worked:

//Brocfile.js
var mergeTrees  = require('broccoli-merge-trees');
var compileSass = require('broccoli-sass');

sourceTress = ['app/styles'];
var phoneCss   = compileSass(sourceTress, 'phone.scss',  'assets/phone.css');
var tabletCss  = compileSass(sourceTress, 'tablet.scss', 'assets/tablet.css');
var pcCss      = compileSass(sourceTress, 'pc.scss',     'assets/pc.css');

var emberAppTree = app.toTree();
module.exports = mergeTrees([emberAppTree, phoneCss, tabletCss, pcCss]);