This example demonstrates a minimal modular setup for D3 v7, rendering a static text message to an SVG canvas that fills the browser viewport. The code uses `d3.select` to append an SVG element sized to `window.innerWidth` and `window.innerHeight`, then applies a custom reusable module via `svg.call(mod)`. The module, defined in a separate file, exposes a `val1` setter and appends a text element with the provided string. It illustrates a clean, component-based pattern for organizing D3 code without any data binding or interaction.