This example combines five separate D3.js scripts, each generating a distinct SVG visualization appended sequentially to the page. The visuals include a red circle, a steelblue bar chart, a green line chart, a scatter plot of unlabeled points, and a pie chart with a categorical color scale. The code relies on core D3 v7 APIs such as `d3.select`, `d3.line`, `d3.pie`, `d3.arc`, and `d3.scaleOrdinal`. No external data is used; all datasets are hardcoded arrays. The visualizations are rendered as static SVG elements and initiated via `DOMContentLoaded` event listeners.