【pre】
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'>
window.onload=function(){
document.querySelector("div").style.background = "black";
var pre = document.createElement("pre");
pre.textContent = document.body.innerHTML.trim();
document.body.appendChild(pre);
}
</script>
</head>
<body>
<div>first div</div>
<div>second div</div>
</body>
</html>
