JSFiddle - React, Tailwind, and code Playground

HTML

<div class='container'>

  <div class='third-box'>Third</div>
  
  <div class='first-second'>
    <div class='first-box'>First</div>
    <div class='second-box'>Second</div>
  </div>
  
</div>

CSS

.container {
  width: 400px;
}

.first-second {
  overflow: hidden;
}

.first-box {
  float: left;
  background-color: coral;
}

.second-box {
  overflow: hidden;
  background-color: aquamarine;
}

.third-box {
  float: right;
  background-color: salmon;
}