diff -r ee144ed6fb03 -r 1ee4e482bfe7 gulpfile.js
--- a/gulpfile.js	Thu Feb 13 12:11:01 2020 +0100
+++ b/gulpfile.js	Mon Jun 29 22:33:36 2020 +0200
@@ -1,53 +1,35 @@
-var gulp = require('gulp'),
-	concat = require('gulp-concat');
+
+const { src, dest, task, watch, parallel } = require('gulp');
+const concat = require('gulp-concat');
+const less = require('gulp-less');
 
-var package = require("./package.json"),
-	scripts = package.scripts;
+const
+	package = require('./package.json'),
+	paths = package.paths;
+
+
+task('css', function() {
+	return src(paths.less_main, { cwd: paths.less_base })
+		.pipe(less())
+		.pipe(dest(paths.less_target));
+});
 
 
-/** Fix pipe function */
-function fixPipe(stream) {
-	var origPipe = stream.pipe;
-	stream.pipe = function (dest) {
-		arguments[0] = dest.on('error', function (error) {
-			var nextStreams = dest._nextStreams;
-			if (nextStreams) {
-				nextStreams.forEach(function (nextStream) {
-					nextStream.emit('error', error);
-				});
-			} else if (dest.listeners('error').length === 1) {
-				throw error;
-			}
-		});
-		var nextStream = fixPipe(origPipe.apply(this, arguments));
-		(this._nextStreams || (this._nextStreams = [])).push(nextStream);
-		return nextStream;
-	};
-	return stream;
-}
-
-var origSrc = gulp.src;
-
-gulp.src = function() {
-	return fixPipe(origSrc.apply(this, arguments));
-};
+task('scripts', function() {
+	return src(paths.sources, { cwd: paths.base })
+		.pipe(concat(paths.target.replace(/{version}/, package.version)))
+		.pipe(dest(paths.base));
+});
 
 
-// Gulp tasks
-gulp.task('scripts', function() {
-	return gulp.src(scripts.sources, {cwd: scripts.base})
-		.pipe(concat(scripts.target.replace(/{version}/, package.version)))
-		.pipe(gulp.dest(scripts.base));
+task('scripts_core', function() {
+	return src(paths.core_sources, { cwd: paths.base })
+		.pipe(concat(paths.core_target.replace(/{version}/, package.version)))
+		.pipe(dest(paths.base));
 });
 
-gulp.task('scripts-core', function() {
-	return gulp.src(scripts.core_sources, {cwd: scripts.base})
-		.pipe(concat(scripts.core_target.replace(/{version}/, package.version)))
-		.pipe(gulp.dest(scripts.base));
-});
 
-gulp.task('watch', function() {
-	gulp.watch(scripts.sources, {cwd: scripts.base}, ['scripts', 'scripts-core']);
-});
-
-gulp.task('default', ['scripts', 'scripts-core', 'watch']);
+exports.default = function() {
+	watch(paths.sources, { cwd: paths.base }, parallel('scripts', 'scripts_core'));
+	watch(paths.less_sources, { cwd: paths.less_base}, parallel('css'));
+};