var gulp   = require('gulp');
var stylus = require('gulp-stylus');
var concat = require('gulp-concat');
var Filter = require('gulp-filter');

gulp.task('css',function () {

    var filter = Filter('**/*.styl',{ restore: true });

    return gulp.src([
            './styles/stylus/**.styl','./styles/css/**.css'
        ])
        .pipe(filter)
        .pipe(stylus())
        .pipe(filter.restore)
        .pipe(concat('out.css'))
        .pipe(gulp.dest('./styles'));
});