How to organize assembly using gulp?

I decided to switch to Gulp and PostCSS , how can I determine the CSS build order in this picker? In this case, the output should be 2 files, one minified, the other not. Code from gulpfile.js

 "use strict"; var gulp = require('gulp'); var rename = require('gulp-rename'); var postcss = require('gulp-postcss'); var autoprefixer = require('autoprefixer'); var cssnano = require('cssnano'); var nested = require('postcss-nested'); var short = require('postcss-short'); var assets = require('postcss-assets'); var cssnext = require('postcss-cssnext'); gulp.task('css', function () { var processors = [ //autoprefixer({browsers: ['last 12 version']}), //nested, //cssnano(), short, assets({ loadPaths: ['app/src/assets/'], relativeTo: 'app/common.css' }), cssnext, ]; return gulp.src('css/*/*.css') .pipe(postcss(processors)) .pipe(rename('common.css')) .pipe(gulp.dest('app/css')); }); gulp.task('default', function(){ gulp.watch('css/*/*.css', function(){ gulp.run('css'); }) });