Gruntfile.js

module.exports = function(grunt) {
    grunt.initConfig({
        
       pkg: grunt.file.readJSON('package.json'),
       
       /**
        * Sass task
        */
       sass: {
           dev: {
               options: {
                   style: 'expanded',
                   sourcemap: 'none'
               },
               files: {
                   'compiled/style-human.css': 'sass/style.scss'
               }
           },
           dist: {
               options: {
                   style: 'compressed',
                   sourcemap: 'none'
               },
               files: {
                   'compiled/style.css': 'sass/style.scss'
               }                              
           }
       },
       
       /**
        * Autoprefixer
        */
       autoprefixer: {
           options: {
               browsers: ['last 2 versions']
           },
           multiple_files: {
               expand: true,
               flatten: true,
               src: 'compiled/*.css',
               dest: ''
           }
       },
       
       /**
        * Watch task
        */
       watch: {
           css: {
               files: '**/*.scss',
               tasks: ['sass', 'autoprefixer']
           }
       }
    });
    
    grunt.loadNpmTasks('grunt-contrib-sass');
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-autoprefixer');
    grunt.registerTask('default', ['watch']);
};