gulpfile.js

var gulp = require('gulp');
var livereload = require('gulp-livereload');
var stylus = require('gulp-stylus');
var autoprefixer = require('gulp-autoprefixer');

gulp.task('styles', function() {
	return gulp.src('styles/task*.styl')
		.pipe(stylus())
		.pipe(autoprefixer('last 2 versions', 'ie 9', 'android 2.3'))
		.pipe(gulp.dest('build/'));
});

gulp.task('watch', function() {
	livereload.listen();
	gulp.watch('styles/*.styl', ['styles']);
	gulp.watch('build/**').on('change', livereload.changed);
});

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