This skill should be used when auditing slide HTML files (1280x720 or other fixed-viewport layouts) for the common design anti-pattern of excessive whitespace and insufficient information density. It computes a quantitative whiteRatio by rasterizing all visible content elements (text nodes, images, SVGs, canvases, videos) onto a coarse grid and calculating the uncovered fraction of the viewport. Use after an LLM or sub-agent generates slide HTML to catch under-filled layouts before review. Trigger phrases: whitespace audit, slide design audit, coverage ratio, information density check, slide layout review, check slide for empty space, audit my slides, slide HTML coverage …
