Why are scrollbar styles not working?

Question

JavaScript

I wanted to add originality to the site. The idea came after I saw a scroll bar in Google Books , found what it was like, found for example the color of the arrows scrollbar-arrow-color: #fff; Nothing has changed, as with other properties of the scrollbar. What is the secret of Google? How did he do it? It is logical to assume that if this site has done this, then I can do it, or I'm wrong, help me figure out this issue. How to make the same, for example, scrollbar as in books.google?

Answer 1

Judging by getAllUsers, I don't see a promise return there.
return this.sendToBase(querySQL)

Answer 2

15+ jQuery Custom Scrollbar Plugins, Scripts and T...

Answer 3

It is logical to assume that if this site has done this, then I can do it, or I'm wrong

You are mistaken, Google owns magic and it has access to what we, ordinary mortals, have never even dreamed of ;-)