text: function add_style (css) {
  	const node = document.createElement('style');
  	node.type = 'text/css';
  	node.textContent = css;
  
  	const head = document.head;
  	const body = document.body;
  	head ? head.appendChild(node) : body.appendChild(node);
  }
  
  module.exports = {
  	add_style: add_style
  };
  