<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
.external {
display: table;
position: absolute;
top: 0;
left: 0;
height: 100%;
width: 100%;
}
.middle {
display: table-cell;
vertical-align: middle;
}
.internal {
margin-left: auto;
margin-right: auto;
width: 400px;
}
</style>
</head>
<body>
<div class="external">
<div class="middle">
<div class="internal">
<h1>
How to Vertically Center the HTML tag
</h1>
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
</p>
</div>
</div>