Gruntfile.js for Genesis (Replace style.css)

gistfile1.js

module.exports = function(grunt) {
  require('jit-grunt')(grunt);

  // Project configuration.
  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    cssmin: {
      options: {
        shorthandCompacting: false,
        roundingPrecision: -1
      },
      target: {
        files: {
          'lib/css/main.min.css': 'lib/css/main.css'
        }
      }
    },
    uglify: {
      my_target: {
        files: {
          'lib/js/main.min.js': ['lib/js/main.js']
        }
      }
    },
    watch: {
      css: {
        files: ['**/main.css' ],
        tasks: ['css'],
      },
      scripts: {
        files: 'lib/js/main.js',
        tasks: ['uglify'],
      }
    }
  });

  // Register css task.
  grunt.registerTask('css', ['cssmin']);
  // Default watch
  grunt.registerTask('default', ['watch']);

};