This fork of the responsive margin convention demonstrates a reusable D3.js v5 component that fills the browser viewport and redraws on window resize. The code builds an SVG with a rounded rectangle plot area, plus labeled x- and y-axes, using `d3.axisBottom` and `d3.axisLeft`. A custom `marginConvention` function computes inner dimensions, while `d3.select` and data joins update the chart. The example shows how to structure a responsive visualization with configurable theme properties for axis strokes, fills, and font sizes.