vertical center in a div code example

Example 1: center elements vertically in div

.container {        
    display: flex;
    align-items: center;
}

Example 2: vertical align div

HTML:
<div class="ext-box">
	<div class="int-box">
		<h2>Some txt</h2>
		<p>bla bla bla</p>
	</div>
</div>

CSS:
div.ext-box { display: table; height: 100%; width:100%;}
div.int-box { display: table-cell; vertical-align: middle; }