SVG Fundamentals
This example demonstrates the foundational structure of SVG-based data visualization, using a minimal HTML page that loads CSS and JavaScript. It introduces the core concepts of the SVG specification, such as coordinate systems and the `<svg>` element, while emphasizing the separation of markup, styling, and interactivity. The code relies on raw SVG APIs and vanilla JavaScript, with no external libraries, to illustrate how visual elements are declared and manipulated directly in the browser. The approach highlights the essential building blocks for more complex visualization frameworks like D3 or React-based charting libraries.