Vega-Lite API Part I
This example visualizes CSS named colors as an arc diagram, where each color name is mapped to a radial segment and its hue determines the stroke color. A tooltip reveals the color name on hover, and the chart fills the entire browser window with a dark, high-contrast theme. The visualization is built using the Vega-Lite API, which composes a single `markArc` encoding with `fieldN` mappings for position, color, and tooltip. Data is loaded asynchronously from a CSV file via `d3.csv`, while the view is rendered as SVG using Vega, Vega-Lite, and the vega-tooltip handler.