Portfolio Section - Adding Progress Scroll Bar

Hi everyone, 

Very early days of latest site dev but I saw a site that I'm thinking of using for inspiration on a couple of functionality bits, and wondered if anyone had any input on CSS to achieve this - doesn't appear to be an option of SQSP standard Portfolio sections. 

Is it possible to introduce a progress scroll bar to a Portfolio section only? I've added to entire site before, but never this. 

Here's a link to the site I've been looking at - https://wearemucho.com/ . You'll see it's the first thing above the fold, with progress scroll bar sitting underneath . Really interested to know if there's a way to build this into the upcoming site. 

Any (all) input welcome. 

Thanks

Marc

Just bumping this post-Christmas to see if anyone has any ideas?

Thanks
Marc