I needed to divide a form with many fields into two columns.
After spending a long time clicking "last in line" and moving fields around, I gave up. Every time a new field came, it all had to be moved around again. My patience ran out.
But why make it so difficult.
A single class, 20 lines jQuery, it all seems like I had dreamed of. It took under 10 minutes and is easy to maintain.
This is a very simple example. Of course, it can be styled much more. And if the right side has flow down below left, add a little @media ....