Border between columns

You want something like this?
https://postimg.org/image/rlnsry0bf/

If yes, the code:
https://gist.github.com/luizbills/05ab820f35c4218d6605e05d85697b7e

I tried something similar — but, as I originally said, the borders are not continuous. Using the CSS you suggest, but changing the height from 100px to 100%, I get this: https://postimg.org/image/tt4nfg2gr/
I can get what I want by setting the height to, say, 1000px, but then the borders continue through the bottom of the page and extend the page. There is no setting that would work for all window sizes.

Use breakpoints to make it works with different windows size.

The version I just released forces the columns to be equal heights ??