Equalizing Flixbox Height

I have three flipboxes, all in a row. They all have the same size cover image and icon. However, the sizes seem to depend entirely on what text is on the back. I can’t find a way to force them to be the same height. I tried to put in 100% in Style-Height, but that resulted in showing only the top third part of the image. :/ I would really appreciate your help.

https://wordpress.org/plugins/codelights-shortcodes-and-widgets/

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