JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
  <div class="child left">Left</div>
  <div class="child center">Center</div>
  <div class="child right">Right</div>
</div>

CSS

.parent {
  display: flex;
  height: 100vh;

}

.child {
  flex-grow: 1;
}

.left {
  background: #ddd;
}

.center {
  background: #666;
}

.right {
  background: #999;
}