JSFiddle - React, Tailwind, and code Playground

HTML

<div class="shell">
<div class="container">

  <div class="red">Red</div>
  <div class="green">Green</div>
  <div class="blue">Blue</div>
</div>
</div>

CSS

html, body {
  height: 100%;
}
.shell {
  height: 100%;
  margin: 0;
  text-align: center;
  width: 100%;
}

.shell:before {
  content: ' ';
  display: inline-block;
  height: 100%;
  vertical-align: middle;
  margin-right: -0.25em;
}

.container {
  width: 100px;
  color: #fff;
  display: inline-block;
  margin: auto;
  vertical-align: middle;
}

.red {
  background: red;
  height: 100px;
  line-height: 100px;
  width: 100px;
  color: #fff;
  border-radius: 50%;
  margin-bottom: 10px;
}

.green {
  background: green;
  height: 100px;
  line-height: 100px;
  width: 100px;
  color: #fff;
  border-radius: 50%;
  margin-bottom: 10px;
}

.blue {
  background: blue;
  height: 100px;
  line-height: 100px;
  width: 100px;
  color: #fff;
  border-radius: 50%;
}