Embedded CSS boundary

The shipping decision is KEEP RAW. Oxfmt formats the surrounding TSRX and JSX through the pinned native adapter, while every byte between a lowercase <style> and </style> is restored exactly. There is no CSS parse, no CSS format time, and no formatter subprocess. The format result reports embedded_parse_count = 0 and embedded_format_ns = 0.

Select a diagram node to read its explanation.

Embedded CSS boundary. The current boundary records raw style payloads as opaque spans, keeps them out of the JavaScript AST, and restores their original bytes after formatting.

This is a compatibility boundary, not a shortcut. At the pinned OXC revision, OXC's CSS formatter is an unpublished workspace crate that pulls a registry copy of a crate the formatter itself takes from git. OXC resolves that duplicate with a [patch.crates-io] entry, and applying one downstream would break this project's no-patch, no-fork contract, so this waits on upstream.

The exact evidence hashes, pinned source links, shipping invariants, and requalification conditions live in docs/architecture/css-boundary.json. The gate fails if CSS crates or a Cargo patch enter the product graph, if formatter source gains a subprocess path, if the constants stop reporting zero hidden CSS work, or if a real raw payload changes.

We re-evaluate only after official OXC exposes a consumable same-allocator CSS path without downstream patching. That candidate must then retain source fidelity, fail-closed behavior, convergence, and the established native performance and memory budgets on the Markless corpus.