Hello HTML
This example displays a simple smiley face constructed from SVG primitives, with a yellow circular head, black outline, two eyes, and an arc-shaped mouth. The visualization uses a React component to define the SVG structure, while D3’s `arc` API generates the mouth path geometry. Rendering relies on ReactDOM to mount the component into the HTML page, with D3 v7 loaded via CDN. The code demonstrates the integration of React’s declarative syntax with D3’s geometric utilities, using explicit pixel coordinates for layout.