This example displays a simple yellow smiley face built from three SVG circles: a large face outline and two smaller eyes. It uses React (version 16.9) to render the SVG elements declaratively, computing positions from constants like `centerX`, `centerY`, and `eyeOffsetX`. The face is drawn with a yellow fill, black stroke, and a stroke width of 10, while the eyes are plain black circles. The code defines the layout entirely with JavaScript variables and React components, avoiding any external data or geometry libraries.