Check out example codes for "vertical align center css". It will help you in understanding the concepts better.

Code Example 1

<style>
.container { 
  height: 200px;
  position: 
  relative;
  border: 3px solid green; 
}

.center {
  margin: 0;
  
  position: absolute;
  top: 50%;
  left: 50%;
  -ms-transform: 
  translate(-50%, -50%);
  transform: translate(-50%, -50%);
}
</style>

<div 
  class="container">
  <div class="center">
    
  <p>I am vertically and horizontally centered.</p>
  </div>
</div>

Code Example 2

.center {
  display: flex;
  justify-content: center;
  
  align-items: center;
  height: 200px;
  border: 3px solid 
  green; 
}

Code Example 3

.container{	
	margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
  	width: /* Define the width here; */
    height: /* Define the height here; */
}

/*You have to define the width and height! */

Code Example 4

/* Answer to: "css vertical align middle" */

/*
  Go to: https://www.w3schools.com/css/css_align.asp
  Here you can learn many ways to align horizontal and vertically!
  My favourite method is below:
*/

.center {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 200px;
  border: 3px solid green;
}

Code Example 5

/* No Flexbox */
.parent {
  position: relative;
}
.child {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

/* With Flexbox */

.parent {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

Code Example 6

align verticaly

Learn ReactJs, React Native from akashmittal.com