Create a 600 by 600, 1.5-second looping animation. Add a pale rounded button backplate 380 by 160 pixels at the canvas center. Draw a purple right arrow as three rounded rectangles and group them. Move only the arrow group 24 pixels right at 0.75 seconds and back by 1.5 seconds. Keep the button still. Match first and last poses exactly, leave room around the arrow, and save the editable project.