I made this parallax Tokyo city skyline with pure CSS and SVG!
Live Site: https://harryli0088.github.io/css-parallax-city-skyline/
Inspired by and built off of Jeremy Hull's CodePen: https://codepen.io/coderado
I used Boxy SVG Editor to make the mountains and clouds: https://boxy-svg.com/app/
Play around with sandbox.html and sandbox.js if you want to programmatically generate SVG. Then you can copy the generated HTML/SVG content into index.html and remove the script import.