So I'm attempting to create a grid like this

Where I have the top and bottom posts the same size and have one post in the middle slim down and auto-fill the remaining space.
Here is my code
<section class="posts-grid">
<article class="post">
<img src="https://blog.flyingsaucer.nyc/hs-fs/hubfs/blog/pitchadri.png?width=1464&name=pitchadri.png" alt="">
<div class="blog-listing-info">
<a href="#">
<h2 class="blog-listing-title">13 things to make your US and UI design much better</h2>
</a>
<p class="blog-listing-tag">Design - 11 min read</p>
</div>
</article>
<article class="post">
<img src="https://blog.flyingsaucer.nyc/hs-fs/hubfs/blog/pitchadri.png?width=1464&name=pitchadri.png" alt="">
<div class="blog-listing-info">
<a href="#">
<h2 class="blog-listing-title">13 things to make your US and UI design much better</h2>
</a>
<p class="blog-listing-tag">Design - 11 min read</p>
</div>
</article>
<article class="post long-post">
<div class="blog-listing-info">
<a href="#">
<h2 class="blog-listing-title">13 things to make your US and UI design much better</h2>
</a>
<p class="blog-listing-tag">Design - 11 min read</p>
</div>
</article>
<article class="post">
<img src="https://blog.flyingsaucer.nyc/hs-fs/hubfs/blog/pitchadri.png?width=1464&name=pitchadri.png" alt="">
<div class="blog-listing-info">
<a href="#">
<h2 class="blog-listing-title">13 things to make your US and UI design much better</h2>
</a>
<p class="blog-listing-tag">Design - 11 min read</p>
</div>
</article>
<article class="post">
<img src="https://blog.flyingsaucer.nyc/hs-fs/hubfs/blog/pitchadri.png?width=1464&name=pitchadri.png" alt="">
<div class="blog-listing-info">
<a href="#">
<h2 class="blog-listing-title">13 things to make your US and UI design much better</h2>
</a>
<p class="blog-listing-tag">Design - 11 min read</p>
</div>
</article>
<article class="post">
<img src="https://blog.flyingsaucer.nyc/hs-fs/hubfs/blog/pitchadri.png?width=1464&name=pitchadri.png" alt="">
<div class="blog-listing-info">
<a href="#">
<h2 class="blog-listing-title">13 things to make your US and UI design much better</h2>
</a>
<p class="blog-listing-tag">Design - 11 min read</p>
</div>
</article>
</section>
css
.posts-grid {
grid-template-areas:
"post post"
"long-post post"
"post post";
grid-template-columns: 15% 1fr;
grid-template-rows: 80px 1fr;
grid-auto-rows: 385px;
grid-column-gap: 23px;
grid-row-gap: 20px;
height: 100vh;
display: grid;
}
.post { grid-area: post; }
.post.long-post { grid-area: long-post !important; }
I have created a codepen https://codepen.io/ben_bagley/pen/30272c1f61b4f20c080040f5359bd5f1 but as you can see it it's ignoring a good like so

Any help in getting the desired effect is appreciated.