This example presents an empty, rounded rectangle that fills the entire browser viewport as a blank canvas. The visualization uses D3 v5 to select the SVG element and dynamically set its dimensions based on the document body’s client width and height, then appends a single rectangle with a 40-pixel corner radius. The SVG rendering approach relies on the D3 `select` and `append` API, while the fixed-position CSS ensures the graphic stays locked to the screen edges without scrollbars.