how to put everything in the center 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: how to make things center using css

// add to the parent element
.parent{
  	height:100vh;
	display:flex;
  	justify-content: center;
  	align-items: center;
}
or you can use 
.parent{
  	height:100vh;
	display:gird;
  	place-item:center;
}