JSFiddle - React, Tailwind, and code Playground

HTML

<div class="flex">
  <div class="flex_item">1</div>
  <div class="flex_item">2</div>
  <div class="flex_item">3</div>
</div>

<button class="flex">
  <div class="flex_item">1</div>
  <div class="flex_item">2</div>
  <div class="flex_item">3</div>
</button>

CSS

.flex {
  display: flex;
  justify-content: center;
  align-items: stretch;
  width: 300px;
  height: 100px;
  margin: 10px;
  border: dashed gray 1px;
  background: none;
}

.flex_item {
  border: solid red 1px;
}