how to align all items in center in css code example

Example 1: css center everything

/* to make "align-items: center" work: use "min-height: 100vh;"
100vh = 100% Viewport Height */
body {
	display: flex;
	min-height: 100vh;
	flex-direction: column;
	justify-content: center;
	align-items: center;
}

Example 2: align items center css

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