Comment by mrandish

Alex,

It's somewhat ironic that a web page about performant terminal user interfaces uses gratuitously complex CSS mask compositing and cubic gradients which reduce smooth scrolling on my 1 year-old, high-end Dell XPS laptop (>$3k) to Commodore 64 level (on default 'Balanced' battery mode). While it's pretty, it's also just a very subtle, non-critical background animation effect. Not being a CSS guru myself, here's what Gemini says:

> "Specifically, this is a Scrim or Easing Gradient. Instead of a simple transition between two colors, it uses 16 color stops to mimic a "cubic-bezier" mathematical curve. This creates a smoother, more natural fade than a standard linear gradient, but it forces the browser to calculate high-precision color math across the entire surface during every scroll repaint."

My Firefox smooth scrolls like butter on thousands of pages, so you might want ask your web designer to test on non-Mac, iGPU laptops with hiDPI and consider the performance cost of web pages with always-running subtle background animations in a world of diverse hardware platforms. In case it helps, here's the animation with the gradient layers disabled so you can see all 6,400,000 pixels which are being recalculated every scroll line (https://i.imgur.com/He3RkEu.jpeg).