<style>
.root {
  height: 100px;
}

.container {
  height: -webkit-fill-available;
}

.content {
  height: -webkit-fill-available;
  background-color: green;
  width: 100px;
}
</style>
<!-- containing block chain with --fill-available should be resolvable -->
<div class=root>
  <div class=container>
    <div class=content></div>
  </div>
</div>
