JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <div class="blocks">
    <div class="blocks__block-1">1</div>
    <div class="blocks__block-2">2</div>
    <div class="blocks__block-3">3</div>
  </div>
</body>

CSS

body {
    width: 400px;
    height: 400px;
	border: 1px solid green;
	margin: 0;
	padding: 0;
}

.blocks {
	display: flex;
	flex-direction: column;
	justify-content: center;
}

.blocks__block-1,
.blocks__block-2,
.blocks__block-3 {
    padding: 9px;
    border: 1px dashed red;
}