SCSS

by Alex Liu

HTML

<div class="a">
  Ab
</div>

SCSS

html, body{
  height: -webkit-fill-available;
}

body {
  background: #fff;
  font-family: Helvetica;
  display: flex;
  align-items: center;
}

.a{
  background: #77a;
  color: #fff;
  font-size: 20px;
  text-align: center;
  width: 100vw;
  display: flex;
  align-items: center;
  justify-content: center;
  height: calc(50vw);
  
}