Layout – button refusing to move to bottom of container on mobile

https://crystalyaki.ca/test/looking-to-build

The desktop and tablet layout are fine as is, but on mobile phone the button sits on Mike’s head – we’d like to fix that. 😉

I’ve tried all the normal settings for moving a button to the bottom of a container but it won’t budge. I probably have another setting in there that’s preventing it, but can’t figure out what.

I’d like the button centred at the bottom with 20-40px margin on the bottom.