Demo: CSS inset-inline-end

<div class='container'>
  <div class='box'>Hello, World!</div>
</div>

.container {
  display: flex;
  justify-content: flex-end;
  height: 100vh;
  background-color: #f0f0f0;
  padding-inline-end: 20px;
}

.box {
  background-color: #4CAF50;
  color: white;
  padding: 20px;
  inset-inline-end: 20px;
  position: relative;
}

// No JavaScript required for this demo