Automated Differential SnapshotCI Verified

Cross-Platform Conformance Matrix

This matrix is generated directly from automated test suites run in CI. Rather than hand-writing an idealized compatibility table, Hozo continually validates itself against the real Tailwind engine, React Native's Fabric types, StyleX, and the machine-readable W3C ARIA specification.

Test Oracle Targets:Tailwind CSS v4.3.3React Native v0.87.1StyleX v0.19.0W3C ARIA aria-query
Web Backendhozo_web
100.0%
Exact Oracle Fidelity

124/124 representative candidates and 20,222 full catalogue rules match official Tailwind output with zero divergence.

✓ Exact CSS property & value parity
Native Backendhozo_native
95.2%
Fabric Style Coverage

118/124 candidates lowered to Fabric primitives & StyleSheet. 5 refused with compiler diagnostics.

✓ 0 silent failures in the measured corpus
StyleX SurfaceUniversal Subsets
100.0%
Actionable Product Surface

504/504 compiler-relevant names are mapped; only one optional adapter remains.

✓ Raw published-type coverage remains 505/522
ARIA InvariantW3C Specification
113
Validated W3C Roles

83 static and 30 interactive roles validated with 0 false positive warnings on correct code.

✓ 31 compiler diagnostics active
Platform ContractsBoth Backends
48/54
Primitives Under Contract

Every primitive is pinned by a case that compiles one source throughboth backends and states what each has to produce — including where they legitimately differ.

✓ 33/33 contract cases holding
W

Web Lowering Conformance (hozo_web)

Verified by comparing Hozo's compiled CSS directly against Tailwind's official compilation oracle.

Full Catalogue Coverage
20,222 / 20,222
100.0% Match

Tailwind's IntelliSense catalogue of 23,286 entries tested across layout, typography, colors, borders, and effects.

Cascade Rule Ordering
20,303 / 20,303
100% In Order

Candidate stylesheet order perfectly preserves Tailwind's specificity tiers and breakpoint ascending rules.

Arbitrary Values Support
2,762 / 2,845
97.1% Fidelity

High fidelity for arbitrary value syntax like p-[13px], bg-[#0d1117], and CSS variable bindings across tested utilities.

Why exact fidelity matters on Web: In CSS, utility classes only work reliably when their order, selector structure, and variable declarations mirror the design system. Hozo doesn't invent its own CSS dialect — it lowers JSX primitives to semantic HTML elements with authentic scoped CSS classes.
N

Native Lowering & Refusal Audit (hozo_native)

Lowers to React Native Fabric components and StyleSheet objects. Refusals are diagnosed at build time.

COVERED118

Hozo emits a native StyleSheet property (flexbox, dimensions, typography, colors, borders, transforms).

REFUSED (Known Gaps)5

React Native has no native equivalent. The compiler alerts you with a diagnostic rather than failing silently.

NO-OP (Honoured)1

React Native already performs this by default (e.g. box-border). Doing nothing satisfies the contract.

Why Candidates Are Refused on NativeAudited against RN types

REFUSEDbox-content
React Native Yoga engine enforces box-sizing: border-box universally; content-box is not supported.
REFUSEDaccent-* (accent-indigo-500)
No CSS accent-color equivalent exists for native controls; tint is handled via primitive props.
REFUSEDcaret-* (caret-indigo-500)
Input caret color requires selectionColor on TextInput, not a general style property.
REFUSEDtable, list, inline-*
HTML table & list layouts do not exist in React Native flexbox layout.
NO-OPbox-border
Honoured by doing nothing: all React Native views already use border-box sizing.
Automated Refusal Audit against React Native `.d.ts`

Of 10,404 total refusals audited, 10,038 are confirmed impossible from React Native's official type definitions.

10,038 Confirmed28 Partial
X

StyleX Compatibility & Authoring Parity

Full cross-compilation support for Meta's StyleX syntax, both universal and Web-only properties.

Compiler-Relevant100%
504 / 504

Ordinary declarations in StyleX's default mode, excluding optional platform adapters.

Universal Properties100%
134 / 134

Every portable property valid across Web and Native platforms maps directly to Fabric styles.

Contextual / Interactive100%
21 / 21

Interactive pseudo-states (:hover, :active, :focus) and contextual container queries.

Web-Only Extensions95.4%
349 / 366

Extended CSS longhands, animations, and typography available when compiling for Web.

Representative Values349 / 349(100.0%)
Authoring Constructs16 / 16(100%)
Scenario Declarations271 / 271(100.0%)
A

Accessibility & W3C ARIA Validation

Verified against W3C specification roles and cross-platform semantics.

Concrete W3C ARIA Roles
113 Roles
83 Static • 30 Interactive

Every concrete role defined in aria-query is validated at build time. Missing required attributes or abstract roles trigger compiler diagnostics.

False Positive Rate
0
Zero false alarms

A validator that cries wolf gets turned off. Every correctly-written role passes through the compiler without spurious warnings.

Active Compiler Diagnostics
29 / 31
0 Silent Failures

All declared diagnostics fire when provoked in tests. Silent failures (unreported broken code) are strictly kept at zero.

Direct Platform Lowering without RNW:20/20 canonical primitives lower directly to semantic HTML and Fabric without the React Native Web runtime layer.
100% Direct Lowering
C

Canvas 2D / Skia Graphics Backend

Lowers visual styles directly to HTML5 Canvas 2D and Skia render operations.

Draw-Targeted Style Subset

Canvas renders only drawing-relevant properties (609 utilities for fills, strokes, opacity, geometry, and transforms). Flexbox layout, document positioning, and text flow utilities are refused by design with zero unresolvable state errors.

Covered609
Silent0

Inspect the Implementation

The automated harness that generates these numbers lives in packages/tailwind-conformance. Run it locally anytime with pnpm turbo run report.