I'm trying to build functionality that is identical to the conditionally sticky footer on this page: https://cashflow.chase.com/increase-cash-in/maximize-your-cash-on-hand.htm
As you scroll down the page, the footer stays in place until a certain point on the page, at which point it just becomes a part of the page flow and scrolls off screen. I need to duplicate that functionality but I'm unable to figure out how they're doing it on that page.
I'm building this functionality inside of a react application if that makes a difference. The footer is coded and is properly functioning as a sticky footer, but does not become part of the page flow at a certain point--it currently just stays sticky all the way down.