JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="left">left</div>
  <div class="content">content</div>
  <div class="right">right</div>
</div>

CSS

* { margin: 0; padding: 0; }
body { background: gray; }

.container { display: flex; }
.left,
.right {
  background: darkred;
  width: 10%;
}

.left,
.content,
.right {
  height: 500px;
}

.content {
  background: silver;
  margin: 0 1px;
  width: 80%;
}