Three animated SVG shapes practice D3 transitions in a React-free setup. An arc pulses between inner and outer radii, while two diagonal lines stretch and contract in sync, each cycling through uptime, wait, and downtime intervals. The code uses `d3.arc` to compute the arc’s path and chained `transition().duration()` calls with `on('end')` callbacks to loop the animations. A static HTML page loads D3 v5 and runs the script in a 200×200 SVG.