'use strict';

window.addEventListener("scroll", () => {
  const articles = document.getElementsByTagName('article');
  const header = document.getElementById('side-bar');

  if(window.pageYOffset >= 500){
    if( header ) {
      header.classList.add('hidden');
    }
    if( articles ) {
      console.log(articles);
      Array.from(articles).forEach( (e) => {
        console.log(e);
        e.classList.add('zen-mode');
      });
    }
  } else {
    if( header ) {
      header.classList.remove('hidden');
    }
    if( articles ) {
      Array.from(articles).forEach( (e) => {
        e.classList.remove('zen-mode');
      });
    }
  }
});