Insert a web frame, or open an .htmlfile, and the frame’s content is HTML and CSS. The Blitz engine — Stylo for styles, Taffy for boxes, Parley for text — is compiled to wasm and lays the source out at the frame’s size. The result is drawn inside the frame on the editor canvas: fills, strokes, text runs, linear, radial and sweep gradients, box shadows and images.
The source lives in the document itself: in the frame’s metadata label when it fits, otherwise in a content-addressed part of the .paged container. It is undoable and travels through IDML.



