clock.html

<!DOCTYPE html>
<html>
<style>

@import url(https://fonts.googleapis.com/css?family=Roboto:500,700);

html {
  color: #fff;
  background-color: #1e1f26;
  font-family: Roboto;
  text-align: center; 
}

#page {
  display: inline-block;
}

#clock {
  font-size: 5em;
  font-weight: 700;
}

  
</style>

<head>
  <meta charset="utf-8"/>
  <title>Clock</title>
</head>

<body>

<div class="page">
  <div id="clock"></div>
</div>


<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js"></script>
<script>
setInterval(function(){document.getElementById('clock').innerHTML = moment().format('HH:mm:ss');}, 1000);
</script>

</body>
</html>