JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <span></span><span></span>
</div>

CSS

div {
  border: 1px solid gray;
  display: inline-block;
  font-size: 0px;
}
span {
  width: 13px;
  height: 25px;
  display: inline-block;
}
span:not(:last-child) {
  border-right: 1px solid gray;
}