text: var gulp = require('gulp');
  
  // gulp plugins and utils
  var gutil = require('gulp-util');
  var postcss = require('gulp-postcss');
  var sourcemaps = require('gulp-sourcemaps');
  var imagemin = require('gulp-imagemin');
  
  // postcss plugins
  var autoprefixer = require('autoprefixer');
  var colorFunction = require('postcss-color-function');
  var cssnano = require('cssnano');
  var customProperties = require('postcss-custom-properties');
  var easyimport = require('postcss-easy-import');
  
  gulp.task('images', function() {
      return gulp.src('assets/images/*')
          .pipe(imagemin())
          .pipe(gulp.dest('assets/built/images/'))
  });
  
  gulp.task('css', function () {
      var processors = [
          easyimport,
          customProperties,
          colorFunction(),
          // autoprefixer({browsers: ['last 1 versions']}),
          cssnano()
      ];
  
      return gulp.src('assets/css/*.css')
          .pipe(sourcemaps.init())
          .pipe(postcss(processors))
          .pipe(sourcemaps.write('.'))
          .pipe(gulp.dest('assets/built/'))
  });