Smiley Face Part 1
This example draws the upper half of a smiley face using React for component structure and D3’s `arc` generator to create the mouth as a thick, semi-circular path. The SVG rendering includes an orange background circle with a black stroke, two black eyes positioned with fixed offsets, and a mouth arc whose start and end angles span half a circle. All coordinates are computed relative to a center transform, and the code explicitly sets width, height, and stroke widths as constants. The visualization is static, with no interaction or data binding.