Gulp SCSS

gulpfile.js

var gulp = require('gulp');
var sass = require('gulp-sass');
var autoprefixer = require('gulp-autoprefixer');
var sourcemaps = require('gulp-sourcemaps');
var browserSync = require('browser-sync').create();
var rename = require("gulp-rename");
var cleanCSS = require('gulp-clean-css');

var input = './assets/css/sass/main.scss';
var output = './assets/css';

var sassOptions = {
  errLogToConsole: true,
  outputStyle: 'expanded'
};

var autoprefixerOptions = {
  browsers: ['last 2 versions', '> 5%', 'Firefox ESR']
};

gulp.task('serve', ['sass'], function() {
    browserSync.init({
        server: {
            baseDir: "./"
        }
    });

    gulp.watch("assets/css/sass/**/*.scss", ['sass']);
    gulp.watch("*.html").on('change', browserSync.reload);
});

gulp.task('sass', function() {
    return gulp
        .src(input)
        .pipe(sourcemaps.init())
        .pipe(sass(sassOptions).on('error', sass.logError))
        .pipe(sourcemaps.write())
        .pipe(autoprefixer(autoprefixerOptions))
        .pipe(cleanCSS({compatibility: 'ie8'}))
        .pipe(rename("style.min.css"))
        .pipe(gulp.dest(output))
        .pipe(browserSync.stream());
});

gulp.task('watch', function() {
  return gulp
    // Watch the input folder for change,
    // and run `sass` task when something happens
    .watch(input, ['sass'])
    // When there is a change,
    // log a message in the console
    .on('change', function(event) {
      console.log('File ' + event.path + ' was ' + event.type + ', running tasks...');
    });
});

gulp.task('default', ['serve']);

gulp.task('prod', function () {
  return gulp
    .src(input)
    .pipe(sass({ outputStyle: 'compressed' }))
    .pipe(autoprefixer(autoprefixerOptions))
    .pipe(gulp.dest(output));
});

package.json

{
  "name": "konf-landing-page",
  "version": "1.0.0",
  "description": "",
  "main": "gulpfile.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "dev": "gulp"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/gustavoquinalha/konf-landing-page.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/gustavoquinalha/konf-landing-page/issues"
  },
  "homepage": "https://github.com/gustavoquinalha/konf-landing-page#readme",
  "dependencies": {
    "gulp-sass": "^2.3.2"
  },
  "devDependencies": {
    "breakpoint-sass": "^2.7.0",
    "browser-sync": "^2.18.2",
    "gulp": "^3.9.1",
    "gulp-autoprefixer": "^3.1.1",
    "gulp-clean-css": "^3.9.2",
    "gulp-rename": "^1.2.2",
    "gulp-sass": "^2.3.2",
    "gulp-sourcemaps": "^2.2.0"
  }
}