JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="first">a</div>
  <div class="second">b</div>
  <div class="third">c</div>
</div>

CSS

.container {
  display: flex;
  flex-wrap: wrap;
}

.first {
  background-color: #0afc12;
  flex-basis: 33%;
  height: 400px;
}

.second {
  background-color: #17cfe3;
  flex-basis: 66%;
  height: 200px;
}

.third {
  background-color: #fcba03;
  flex-basis: 33%;
  height: 200px;
}