Smiley Face part 1
A smiling face is drawn using yellow and black SVG circles, with a dark arc for the mouth. Built with React and rendered to SVG, the visualization constructs the face from separate components for the background circle, eyes, and mouth. It uses the `arc()` generator from D3 (d3.v7) to define the mouth’s annular sector, and positions elements via SVG transforms in a 960×500 viewport.