Developing Website with Expanding/Contracting sections/bars while scrolling to navigate?

I'm doing a website as a way to venture into web development. The developer I was doing the website with dropped the project after coding a little bit of it in ruby, leaving me at a loss for what to do. I know ruby, but I want to see if there's a way to do this without ruby and just html/css + javascript.

I am trying to make a website that is basically a bunch of rows of horizontal bars, each one being a section or a page. As you scroll, one bar expands to take up part of the window (not the entire window to leave room for the bars that haven't expanded). So you view one full section at a time with the other sections still visible at the top and bottom (as bars), and you scroll to navigate through each section. The idea is for each section to stretch to full proportions, and when the user moves to the next section, its content becomes squished into a little bar again.

Does anyone have any advice to help me move forward with this?