<div class="container">
  <div class="element"></div>
</div>

.container::before {
  content: '';
  display: inline-block;
  height: 100%;
  vertical-align: middle;
  margin-left: -1ch;
}
.element{
  display: inline-block;
  vertical-align: middle;
  margin: auto;
  width: 100%; height: 50vh;
  background:tomato
}
/* just aesthetics */
.container{
  width:90vw;
  height: 90vh;
  border: 3px solid steelblue;
  margin: auto;
}

body{
  height: 100vh;
  display:flex;
  background: azure;
}