Change
overflow: hidden;
to
overflow: auto;
This will allow users to see your content, but it will introduce two new problems:
1) There will be a scroll bar on the right hand side if needed.
2) When users scroll, the boxes on the left will move away from the boxes on the right.
This is because the two sets of boxes are in different <div>
‘s. I can’t think of a way to avoid this at the moment.