This example displays a hierarchical tree from a JSON dataset, with nodes labeled and connected by curved links whose stroke thickness varies with child data size. It uses D3.js v5, including the `tree` layout, `hierarchy` for data nesting, and `linkVertical` for path generation. The SVG rendering is controlled via `select`, with zoom functionality integrated through the `zoom` and `event` APIs. Text labels use a Playfair Display font, styled with a white shadow effect from CSS.