#page .page-section {position: sticky!important; top: 0px!important} html {scroll-behavior: smooth} 

Here is the code from this tutorial with a little bit of a shadow to create even more depth between these pages sections. 

#page .page-section {position: sticky!important; top: 0px; box-shadow: 5px 5px 15px rgba(0,0,0,0.8)!important} html {scroll-behavior: smooth}