The other Labs pages have a sparse twinkling background visible right now behind this text. It's a single SVG with a handful of <circle> elements, each driven by an independent CSS keyframe animation. All the per-frame work happens in the browser's compositor, so CPU cost is effectively zero.
The sliders below drive those parameters. Whatever you set here is saved to localStorage and applied to every other Labs page on this device. The background re-renders live as you drag — the page you're on is the same canvas, so you can preview against real content.
To turn the background off entirely on this device, drag count or peak opacity to 0. To reset everyone-else-on-this-device-too, hit reset.
One detail worth noting: the dot positions come from a saved seed, not a fresh roll, so the same field reappears on every refresh and on every other Labs page — you keep whatever layout you've got. The sliders here control density and timing against that fixed layout; dragging them previews the change without moving the dots (raising count appends new dots rather than reshuffling). The regenerate positions button rolls a new seed when you want a different field; reset restores the default settings but leaves the layout alone.