css vertical align with flexbox

.Aligner {
  display: flex;
  align-items: center;
  justify-content: center;
}

.Aligner-item {
  max-width: 50%;
}

.Aligner-item--top {
  align-self: flex-start;
}

.Aligner-item--bottom {
  align-self: flex-end;
}

<div class="align-vertically">
  I am vertically centered!
</div>


/*Css  */

.align-vertically {
  background: #13b5ea;
  color: #fff;
  display: flex;
  align-items: center;
  height: 200px;
}