align div align center top and vertically code example

Example 1: css align items vertical center

.parent {
  display: flex;
  justify-content: center;
  align-items: center;
}

Example 2: how to center horizontally and vertically block div

#html code
<div class="parent">
	<h1 class="child">CSS is cool</h1>
</div>

#css code
.parent{
  display:grid;
  place-items:center;
  
  width:560px; 
  height: 560px;
}