Parallax scrolling with CSS variables | basicScroll
Don’t let the title fool you—this isn’t just for parallax scrolling (thank goodness!)—it’s for triggering any CSS updates based on scroll position. Using CSS custom properties makes a lot of sense. The JavaScript/CSS bridge enabled by custom properties is kind of their superpower. (That’s one of the reasons why I don’t like calling them “CSS variables” which makes them sound like Sass variables—they’re so much more than that!)