CSSketch

CSSketch is an open-source Sketch 3 plugin that lets designers control layers through CSS-style rules. A stylesheet can be attached to individual Sketch pages and used to change layout, colors, borders, shadows, and text properties. Selectors can target artboards, text layers, names, and class-like layer identifiers. The plugin detects stylesheet changes and reapplies them when the file is saved, creating a code-driven design workflow. Sass and Less support allows designers to use variables, functions, and other stylesheet conveniences. CSS processing is powered by the system WebKit engine, and stylesheet paths are stored inside Sketch documents for reuse. The project is no longer maintained and does not work with current versions of Sketch, but it remains an interesting example of programmable visual design tooling.