Hi There,
Thanks for writing in again!
Yes, you can make it through custom CSS.
Please follow the steps.
Please make the columns position relatives. You can add this code to each column element CSS.
$el{
position: relative;
}

Then create one custom class name to buttons.

Then add this CSS in your theme option -> CSS
.custom-bottom {
position: absolute;
bottom: 10px;
left: 50%;
transform: translate(-50%); /* Standard syntax */
}
Hope this works!
Remember as mentioned by @Rad the column only depends on content. Uf you will add more content then you have to adjust it further.
As this is something custom CSS, we can’t help you further.
Thanks