JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box ad"> ad </div>
<div class="box middle"> middle </div>
<div class="box invisible"> right </div>
<!-- invisible -->

CSS

body {
  border: 1px solid black;
  display: flex;
}

.box {
  border: 1px solid black;
  width: 50px;
  height: 100px;
}

.invisible {
  margin-left: auto;
  margin-right: auto;
  visibility: hidden;
}

.middle {
  margin-left: auto;
}

.ad {
  margin-left: auto;
}