if you want it to be fixed at bottom of the page You can simply add this css

body {
   padding-bottom:52px;
}

 .description{
   position:fixed;
   bottom:0;
}

If I am understanding right, you don't know how to find what to change because there are so many lines. You should use Chrome Developer Tools.

You must right click > inspect the part you want to move to the bottom of the page. Then you can search (CTRL + F) for a spesific part of the code and find what you need.

Here is a more cleaner explanation.

https://nira.com/chrome-developer-tools/#:~:text=From%20the%20Chrome%20menu%3A,web%20page%20you're%20on.

Finally you can make the change you need.