body {
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;flex-wrap: wrap;
  height: 100vh;
  font-size: 30px;
  font-weight: bold;
  font-family: "Tahoma";
}

var resizeTimeout;
window.addEventListener('resize', function(){
    clearTimeout(resizeTimeout);
    resizeTimeout = setTimeout(function () {
      if (document.body.clientWidth < 1000) {
            document.body.innerHTML = "clientWidth < 1000";
        } else {
            document.body.innerHTML = "clientWidth >= 1000";
        }
    }, 100);
}, true);

window.dispatchEvent(new Event("resize"));