Vertical-Align the content in a slideshow? (stretched slides)

Hey there. First of all, thanks for the plug-in. Love it.

I’m using a slideshow (UNSTYLED template) to display some testimonials, and it’s within a Div b/c I wanted a background image behind it.

(About half-way down the page at https://www.AdultsOnlyMagic.com, currently under the heading “a crowd favorite”)

Here’s the section in question:

<div style="background: url('https://adultsonlymagic.com/wp-content/uploads/2018/06/5-stars_iowa-magician-iowa-comedian1.png'); background-size: 100% auto; background-position: center; padding: 0px; margin: 0px;">
[testimonial_view id="1" category="reviews"]
</div>

Some of my slides are different sizes, so to prevent the “bouncing” of the elements below it, I’m using the “set height to match the tallest slide” and “stretch slides vertically.”

My question is… how might I go about *VERTICALLY* centering the content of these slides (they’re only text), so that each of the testimonials is centered vertically?

As-is, all of the content is aligned up at the top, and with the shorter slides, that leaves quite a bit of “white space” beneath it.

This is really just an aesthetic desire, not a functionality issue. Is this possible? It’s probably something ridiculously simple, but I have “CSS brain” right now. I’ve tried a number of different combinations with this, but the solution seems just out of reach.

Thank you.

The page I need help with: [log in to see the link]