document.addEventListener('DOMContentLoaded', ()=>{
'use strict';
let doc = document,
html = [],
info = ['scr', 'wnd'];
html.push('<div class="info"></div>');
doc.body.innerHTML=html.join('');
html = [];
for (let i =0; i<=1; i++){
html.push('<div id = "'+ info[i] + '"></div>' );
doc.querySelector('.info').innerHTML = html.join('');
}
wnd();
doc.querySelector('.info').style.cssText = 'background:rgba(0,0,0,.5);color:#fff;width:190px;padding:15px 25px;font-family:\'Open Sans\',sans-serif;font-size:12px;';
window.addEventListener('resize', wnd);
function wnd(){
doc.querySelector('#scr').innerHTML = 'screen resolution: ' + screen.width + ' x ' + screen.height + ' px';
doc.querySelector('#wnd').innerHTML = 'window size: ' + window.innerWidth + ' x ' + window.innerHeight + ' px';
};
});