Preprocess CSS with the suitcss-preprocessor
$ npm install gulp-suitcss --save-dev
const gulp = require('gulp');
const suitcss = require('gulp-suitcss');
gulp.task('default', () =>
gulp.src('src/index.css')
.pipe(suitcss({
minify: true,
}))
.pipe(gulp.dest('build'))
);
See the suitcss preprocessor API.
Original version by Casear Chu