SVG Fundamentals
This example demonstrates basic SVG shape rendering in a static, fixed-size canvas. A red rectangle with a blue outline, a blue diagonal line, and a circle are each positioned using explicit `x`, `y`, `width`, `height`, `cx`, `cy`, and `r` attributes. The SVG markup is written directly in the HTML, using no JavaScript libraries or data sources. The shapes illustrate fundamental SVG primitives and their styling properties, including `fill`, `stroke`, and `stroke-width`, with no interaction or dynamic behavior.