This example demonstrates a minimal HTML page that uses D3 v6 to render a single blue rectangle onto an SVG canvas within a React-based project structure. The page includes embedded CSS that centers and enlarges body text, while a script appends an SVG element with fixed 500x500 dimensions, then selects and appends a rectangle with hardcoded position and size attributes. The code also logs a message to the browser console and serves as a bare-bones starting point for visualization development.