How do I create a 2 column mobile drop-down menu?

Site URL: https://harpsichord-gazelle-knds.squarespace.com/

Hi! I have currently forced the hamburger menu on desktop AND I have configured the width of the drop down menu just the right width so I can set up a 2 Column Layout for the hamburger drop down menu.

I seem to be stuck to see how I would be able to do this.

I would like to keep the pages on the right side of the hamburger drop-down and put a dividing line in the middle and place an Image > Title > Caption > Social Widgets (stacked vertically) in that order.

Any help would be greatly appreciated!

Thank you and have a wonderful day.

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