Vertical and Horizontal align center

index.html

<div class="full-height">
  <div class="vertical-center">
    <div class="row justify-content-center">
      <div class="col-md-4 col-sm-6 col-12">
        <h1>Some Text</h1>           
      </div>
    </div>  
  </div>                 
</div> 

style.css

.full-height{
  height: calc(100vh - 360px);
  min-height: 100%;
  display: table;
  width: 100%;
}  
.vertical-center{
  display: table-cell;
  text-align: center;
  vertical-align: middle;
}
.row{
  display: flex;
  -webkit-flex-wrap: wrap;
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
}
.justify-content-center {
  -webkit-box-pack: center!important;
  -webkit-justify-content: center!important;
  -ms-flex-pack: center!important;
  justify-content: center!important;
}