how to center align in css 5 ways code example

Example 1: centering horizontally

div.center{display:block;margin:auto;width:50%;}
p.center{text-align: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;
}