The example "Blank Canvas" displays a full-window, rounded-corner rectangle rendered as a blank SVG canvas. It uses D3 v5’s `select` to target the `svg` element, then sets its width and height to match the browser’s viewport dimensions. A single `rect` is appended with a 40-pixel corner radius, creating a simple, empty frame. The styling fixes the body and hides overflow, ensuring the canvas fills the screen without scrolling.