Make containers same height on three column post archive

Dear team,

I have a three column post archive setup. I am trying to make all containers the same height.
I tried it with the following code from your support forum:

.generate-columns {
  display: flex;
}

.generate-columns > .gb-container > .gb-inside-container *:last-child {
  flex: 1;
}

That did the trick with the height, but the width became flexible so that I had different container width for the blog posts depending on title length.

What I want to achieve is: all posts in one row have the same height depending on the largest post container.

Thanks in advance!