Background — Crosses
A grid of spinning asterisk marks on black, every cell tinted one step further along a colour cycle that drifts diagonally and loops seamlessly.
Rows and columns of small multi-spoke marks rotate in unison on a black field. Their colours slide through the spectrum from cell to cell, warm in one corner and cool in the opposite, and the whole gradient scrolls diagonally as the marks turn.
Each mark is a single line segment redrawn a few times at equal rotations, so spoke count is one number. The hue index sums the cell's column and row fractions with the loop angle, advancing exactly one full cycle per loop — which is what makes both the colour drift and an integer rotation speed close without a seam. The palette is swappable (a fixed purple, green or near-black instead of the cycling rainbow), and the row count is derived from the column count and the canvas ratio so cells stay square.
