How to minimize the padding at the bottom of every pages

Hi Community,
I'm trying to work with table of contents, and I've noticed the toggle container is not hidden and cause a huge space at the bottom of every page. How can I remove the bottom space of every page? Is the table of contents toggle container being the cause?
Here's the sample when the Table of Contents toggle bar is open and you can see the long scroll bar indicating the page is too long because of the menu in the Table of contents toggle bar.

And here's the sample when the Table of Contents toggle bar is close and still the scroll bar is long