JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btn" onclick="decalage()">DĂ©calage</button>
<div id="block" class="block"></div>

CSS

.block {
  background:red;
  position:absolute;
  top:50px;
  right:0;
  height:50px;
  width:50px;
}

JavaScript

function decalage() {
	var block = document.getElementById('block');
  block.style.right = '20px';
}