Vertical align with Tailwind CSS across full screen div

How can I vertically align a div with Tailwind? What I want:

-----------------------------------
|                                |
|                                |
|                                |
|             item1              |
|             item2              |
|                                |
|                                |
|                                |
-----------------------------------

What I currently have:

-----------------------------------
|             item1              |
|             item2              |
|                                |
|                                |
|                                |
|                                |
|                                |
|                                |
-----------------------------------

.bgimg {
  background-image: url('https://d1ia71hq4oe7pn.cloudfront.net/photo/60021841-480px.jpg');
}

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/tailwindcss/dist/tailwind.min.css">
<div class="flex flex-col h-screen my-auto items-center bgimg bg-cover">
  <h3 class="text-white">heading</h3>
  <button class="mt-2 bg-white text-black font-bold py-1 px-8 rounded m-2">
    call to action
  </button>
</div>

I have successfully centered on the secondary axis (left-right) with class items-center. Reading the documentation, I tried align-middle but it does not work. I have confirmed the divs have full height and my-auto.

I'm using this version of Tailwind: https://cdn.jsdelivr.net/npm/tailwindcss/dist/tailwind.min.css

Here is a JSFiddle: https://jsfiddle.net/7xnghf1m/2/

Solution

You can also do

<div class="flex h-screen">
  <div class="m-auto">
    <h3>title</h3>
    <button>button</button>
  </div>
</div>