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 At canonical OXC revision 8e0ed2ebb96137fb1611cdbd5742d5cb46037d40, oxc_formatter_css 0.59.0 is an unpublished workspace crate. It consumes registry oxc-css-parser 0.0.7, which in turn requests the registry copy of oxc_allocator; the formatter uses the workspace/git copy. OXC's own workspace resolves the duplicate type graph with a [patch.crates-io] oxc_allocator = { path = ... } entry. Applying that downstream would violate this project's no-patch/no-fork upgrade contract.

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 canonical 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.