JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="a">A</div>
  <div class="a">
    <div class="b">B<br><br><br></div>
    <div class="c">c<br><br></div>
  </div>
</div>

SCSS

.container {
  border: red solid thin;
  display: flex;
  flex-direction: row;
  
  .a {
    background: yellow;
    flex: 1;
    flex-direction: column;
  }
  
  .b {
    background: orange;
  }
  
  .c {
    background: green;
  }
}