JavaScript

You would keep using classic experience of SharePoint sites and provide a Sticky Footer to your final users? This post explain you how to implement one

You would keep using classic experience of SharePoint sites and you wish provide a responsive behavior to your final users ? The new version of PnP-Responsive could be your answer

How to display a dynamic path selector from hierarchical Term Sets based on a SharePoint list/library

To facilitate the users experience and win in productivity, implement a dynamic and reusable TOC will help users to access directly to the targeted chapter