hi all,   I'm having trouble getting pinned sections to work. My page will consist of 6 sections. For debugging purposes, I've created a codepen with only 3. When the second section hits the top of the window, I want it to be pinned. When scrolling further, the section remains pinned, each of the list items needs to get the class "active" and the corresponding block on the left side needs to fade in. When all 3 bullets (and thus divs) have been faded in, the pinned