The age old question of centering a DIV, the modern way.

centering-a-div.css

/*
<div class="wrapper">
  
  <div></div>

</div>
*/


/* With Grid */
.wrapper {
  display: grid;
  place-items: center;
}

/* With Flex */
.wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
}