<div id="root"></div>
// function to render time
function tick() {
  document.getElementById("root").innerHTML = 
    "<div><h1>Hello, world! -- JS DOM Rendering</h1><h2>It is "
      + new Date().toLocaleTimeString()+
    ".</h2></div>";
}

setInterval(tick, 1000);

External CSS

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External JavaScript

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