This example visualizes monthly water level measurements for two wells, with each series distinguished by color in a multi-line chart. A brushable mini-map below the main chart allows users to select a date range, and the brushed region is logged to the console. The visualization is built with D3 v5, using `d3.line`, `d3.scaleTime`, `d3.scaleLinear`, `d3.brushX`, and `d3.nest` to structure the data by well. SVG rendering includes both focus and context panels, with circles marking individual data points and clipped paths ensuring lines stay within bounds.