install node-sass using npm code example

Example 1: node-sass run

npm install node-sass
node-sass ./styles.scss -o ./styles.css

Example 2: node-sass

var sass = require('sass');

sass.render({
  file: scss_filename
}, function(err, result) {
  /* ... */
});

// OR

var result = sass.renderSync({
  file: scss_filename
});