Orrery

Build a fullscreen preloader called Orrery.

Centre a square roughly 56% of the stage's smaller dimension on a near-black background. Inside it nest three concentric circles, each drawn only as a one-pixel border: the outer at full size, the next inset 15%, the third inset 30%. Step their border opacity down from 18% to 14% to 10% white as they go inward, so depth reads without any of them competing.

Give each ring a single marker dot pinned to the top of its own circle and centred on the stroke, shrinking from about 3.6% to 2.8% to 2% of the stage. Make the middle dot the accent colour and leave the others white.

Rotate the rings a full turn on a linear timing function at 2.6s, 4.1s and 6.4s, with the middle one reversed. The point of those three numbers is that they never come back into phase, so the composition keeps producing new arrangements instead of visibly repeating.

Finally, fill the innermost 44% inset with a solid white disc and breathe it between 0.7 and 1 scale, and 0.55 to 1 opacity, on a 2.6s ease-in-out.

Loop forever. Under prefers-reduced-motion, freeze every ring in place.