<div class="container">
  <div class="side-1">Side 1</div>
  <div class="content">Content…<br/>…<br/>…</div>
  <div class="side-2">Side 2</div>  
</div>

@use autoprefixer {
  grid: true;
  browsers: "> 1%"
};

/* (@use is needed in CodePen) */

.container {
  display: grid;
  grid-template-columns: 1fr 3fr 1fr;
  grid-column-gap: 0.5em;  
  grid-template-areas: "a b c"
}

.side-1 {
  grid-area: a;
}

.content {
  grid-area: b;  
}

.side-2 {
  grid-area: c;  
}


/* etc: */

.container > * {
  padding: 1em;
  background: #b3e888;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.