text: 
  
  const boxLeft = document.createElement('div')
  const boxRight = document.createElement('div')
  const boxLeftBottom = document.createElement('div')
  const boxRightBottom = document.createElement('div')
  const setStyle = (elem, obj) => {
      const keys = Object.keys(obj)
      keys.map(e => elem.style[e] = obj[e])
  }
  const bl = {
      position: "fixed",
      top: "1rem",
      left: "1rem",
      color: "#fff",
  }
  const br = {
      position: "fixed",
      top: "1rem",
      right: "1rem",
      color: "#000",
  }
  const bbl = {
      position: "fixed",
      bottom: "1rem",
      left: "1rem",
      color: "#000",
  }
  const bbr = {
      position: "fixed",
      bottom: "1rem",
      right: "1rem",
      color: "#fff",
  }
  setStyle(boxLeft, bl);
  setStyle(boxRight, br);
  setStyle(boxLeftBottom, bbl);
  setStyle(boxRightBottom, bbr);
  
  
  document.body.appendChild(boxLeft);
  document.body.appendChild(boxRight);
  document.body.appendChild(boxLeftBottom);
  document.body.appendChild(boxRightBottom);
  
  
  function setWidth(e) {
      boxLeft.textContent = window.outerWidth;
      boxRight.textContent = window.outerWidth;
      boxLeftBottom.textContent = window.outerWidth;
      boxRightBottom.textContent = window.outerWidth;
  }
  window.addEventListener('resize', repeatOften)
  
  function repeatOften() {
      requestAnimationFrame(setWidth);
  }
  repeatOften();