If anybody is curious, here’s the code for the beachball animation:

https://github.com/daviddarnes/mac-cursors/blob/main/src/_in...

  #beachball svg {
    animation: spin 0.5s infinite linear;
    transform-origin: 51.5% 51.5%;
  }
  
  @keyframes spin {
    from {
      transform: rotate(0deg);
    }
    to {
      transform: rotate(360deg);
    }
  }

This is really hard to get right with rotation transformations, so difficult in fact that most (correct) spinners just do not do rotation transformations and instead have manually pixel-aligned images for each frame of the animation.

Seeing the same thing in desktop Safari.

Just like a real beachball! Classic Apple.