# XWUIChartNestedDonut

A nested-donut chart backed by `XWUIChart` that renders proportions as concentric ring segments, useful for showing a part-to-whole breakdown (and, with multiple series, hierarchy across rings). Provide named `series` of `{ x, y }` slices and pick a `block` (1-4) variant plus a `size` preset; legend and grid auto-toggle per block unless overridden.

## Basic Usage

A single `Share` series of five slices - A 35, B 25, C 20, D 12, E 8 - drawn as a donut.

```example
file: examples/BasicUsage.ts
html: examples/BasicUsage.html
title: Basic Usage
description: A five-slice share breakdown drawn as a nested-donut chart at the md preset.
```

## Budget Plan vs Actual

Two concentric rings put planned spend inside and actual outside on the same categories.

```example
file: examples/BudgetPlanVsActual.ts
html: examples/BudgetPlanVsActual.html
title: Budget Plan vs Actual
description: Planned and actual quarterly spend as nested donut rings.
```

## Traffic Share, This Year vs Last

Inner and outer rings compare last year's and this year's device mix to show the shift.

```example
file: examples/TrafficByDevice.ts
html: examples/TrafficByDevice.html
title: Traffic Share, This Year vs Last
description: Year-over-year device session share as concentric rings.
```

```api
```