JSFiddle - React, Tailwind, and code Playground

HTML

<div class="centre">
  <div class="btn-group">
    <button class="button">My first button</button>
    <button class="button">My second button</button>
    <button class="button">My third button</button>
  </div>
</div>

CSS

html, body, .centre {
    height: 100%;
  width: 100%;
}

div.centre {
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-group .button {
  background-color: #4CAF50;
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  font-size: 16px;
  cursor: pointer;
  float: left;
  display: inline-block;
}

.btn-group .button:hover {
  background-color: #3e8e41;
}