code: function(css) {
    css = css
      // remove comments
      .replace(/\/\*[^\0]*?\*\//g, '')
      // trim space before characters
      .replace(/\s+({|})/g, '$1')
      // trim space after characters
      .replace(/(;|,|:|{|}|^)\s+/g, '$1')
      // trim combinators
      .replace(/\s+(>|\+|~)\s+/g, '$1')
      // remove escaped newlines and spaces
      .replace(/\\\r?\n\s+/g, '')
      // remove trailing semicolons in rules
      .replace(/;(})/g, '$1');
  
    return css;
  }
docs: Optional Minification