Introduction to D3
This example demonstrates basic vector graphics construction with D3 version 7, using d3.select to append SVG shapes (circle, rect, and line) to the document body within a 500×500 coordinate space. The code loads D3 from UNPKG and directly manipulates attributes such as cx, cy, r, fill, width, height, and line endpoints, though it notably contains attribute typos (e.g., `widht` instead of `width`) and redefinitions that the renderer would interpret. The visualization serves as a minimal introduction to D3’s SVG API, highlighting how to create and stylize geometric primitives without data binding or interaction.