Fullscreen API

function enterFullscreen(el = document.documentElement) {
  return el.requestFullscreen?.() || el.webkitRequestFullscreen?.();
}

function exitFullscreen() {
  return document.exitFullscreen?.() || document.webkitExitFullscreen?.();
}

function toggleFullscreen(el) {
  document.fullscreenElement ? exitFullscreen() : enterFullscreen(el);
}

document.addEventListener("fullscreenchange", () => {
  console.log("fullscreen:", !!document.fullscreenElement);
});