This example renders two static gray squares on a blank HTML page, demonstrating the minimal setup required for a web-based visualization. The code uses plain HTML and CSS, with no external libraries or data sources. It includes two identical 50-pixel squares, styled with the `background-color` property, and centers the body text at a large font size. The example serves as a bare bones starting point for building more complex visualizations in a browser, highlighting the foundational structure of an HTML document and its embedded style rules.