Super simple Gulp tutorial for beginners
Jessica Chan
4174

Also I notice something else:

gulp.task('sass', function(){ 
return gulp.src('app/style.scss')
.pipe(sass())
.pipe(cssnano())
.pipe(gulp.dest('dist/css'));
});
As you can see the file : style.scss is inside the "app" folder as per the root folder project is outside , so in case that someone is having the issue with the compile css file.
Thanks in advance.