So in summary, if I'm understanding properly, this uses a few tricks. First resizing the rope (by dragging it) changes the size of a css grid holding all the ot

So in summary, if I'm understanding properly, this uses a few tricks. First resizing the rope (by dragging it) changes the size of a css grid holding all the other elements. Since percentages refer to this parent grid this can be used to resize the other ropes and chains and with the right background + clipping this causes it to "move". For the spinning a sprite sheet is used with the background position depend on the size of the container but with a big enough multiple so we only see one sprite at a time