This example shows a simple line chart of monthly values from a small dataset, with a pattern-filled area emphasizing the data points. The chart uses D3 v4 to render an SVG, mapping dates to a time scale and values to a linear scale. A line path connects the points, and each circle uses a repeating pattern fill. Hovering over a circle highlights it in red, displays its value label, and draws a dashed vertical guide line; moving the mouse away removes the highlight and guide. The visualization employs d3.line, d3.scaleTime, d3.scaleLinear, and event handlers.