optimize and minify css

gulpfile.js

@@ -3,12 +3,14 @@
 var gulp = require('gulp');
 var sass = require('gulp-sass');
 var livereload = require('gulp-livereload');
+var cleanCSS = require('gulp-clean-css');
 
 sass.compiler = require('node-sass');
 
 gulp.task('sass', function () {
     return gulp.src('./sass/**/*.scss')
         .pipe(sass().on('error', sass.logError))
+        .pipe(cleanCSS())
         .pipe(gulp.dest('./css'))
 
 });

package.json

@@ -15,6 +15,6 @@
     "node-sass": "^4.11.0"
   },
   "dependencies": {
-    
+    "gulp-clean-css": "^4.2.0"
   }
 }