Landing Page Project little problem

So I’m on the landing page and doing pretty well so far considering I’ve only been at this for a couple weeks now. The google gods have truly shined upon me through these projects. I am having an issue though. I have three divsin a flexbox that properly convert to column at a certain width. But inside these divsI have buttons that I want to fix to the bottom (at a certain distance from the bottom that i’m not sure of till I get it and can play with it) and center in the div. It may just cause I’ve been at these projects non stop all weekend till the wee-hours of the morning but I just can’t seem to figure this out… And I feel like I should be able to by now.

Here’s a codepen for what I have so far codepen Rhine227/full/xBBGVW
the divs in question are in the last section of the html and the css should be towards the bottom.
I’d also welcome any feedback at all as well. I’m sure there’s plenty I could improve upon.

Add to .pricingOption:

  display: flex;
  justify-content: space-between;