JSFiddle - React, Tailwind, and code Playground

HTML

<div id="side">
  <div class="side-child">
    <img src="https://www.icann.org/assets/icann_logo-52672386035a35504af59606040687c8.png" class="content" />
  </div>
  <div class="side-child">
           <img src="https://www.icann.org/assets/icann_logo-52672386035a35504af59606040687c8.png" class="content" />

  </div>
  <div class="side-child">
          <img src="https://www.icann.org/assets/icann_logo-52672386035a35504af59606040687c8.png" class="content" />

  </div>
</div>

CSS

#side {
  height : 100vh;
  display : flex;
  flex-direction : column;
  width : 50px;
}

.content {
  height : 100%;
  background : #ff0000;
}

.side-child {
  flex-grow : 1;
}