gulpfile

// npm i --save gulp gulp-sass gulp-plumber gulp-autoprefixer gulp-webserver
var gulp = require("gulp"),
    sass = require("gulp-sass"),
    plumber = require("gulp-plumber"),
    autoprefixer = require('gulp-autoprefixer'),
    webserver = require('gulp-webserver');

 gulp.task('styles', function() {
  return gulp.src('scss/*.scss')
    .pipe(plumber())
    .pipe(sass().on('error', sass.logError))
    .pipe(autoprefixer({cascade: false}))
    .pipe(gulp.dest('css'));
});


gulp.task("watch", function() {
    gulp.watch("scss/*.scss", gulp.series('styles'));
});

gulp.task('webserver', function() {
    gulp.src('./')
        .pipe(webserver({
            port: '1234' ,
            fallback: 'index.html',
            livereload: true,
            directoryListing: true,
            open: true
        }));
});

gulp.task('default', gulp.parallel(["styles", "webserver", "watch" ], function() {
  // default task code here
}));