{
  "$schema": "../../schema/run.schema.json",
  "run_id": "tailwindcss--claude-opus-5-5--v5-b--2026-09-27",
  "supersedes": null,
  "replicate_of": "tailwindcss--claude-opus-5-5--v5-a--2026-09-27",
  "library": {
    "name": "tailwindcss",
    "ecosystem": "npm",
    "latest_version_at_test": "4.3.3",
    "latest_version_verified_on": "2026-09-27",
    "latest_version_note": "As `v5-a`: registry `latest` 4.3.3, no 4.4, so the release the prompt names is the one `tailwindcss/v3` was graded against. This draw's own workarounds — the arbitrary properties, `@utility scrollbar-log`, `[&::-webkit-scrollbar-corner]:bg-slate-100`, `[zoom:0.5]`, `scale-50`, and the task 4 stylesheet (nested `@variant` for AND, plain `&:hover, &:focus, &:active` for OR) — were compiled this session against installed 4.2.0, 4.3.0 and 4.3.3; all compile at all three."
  },
  "model": {
    "id": "claude-opus-5-5",
    "label": "Claude Opus 5.5",
    "vendor": "Anthropic",
    "invoked_as": "Agent tool, model alias \"opus\"; prompt sent verbatim from prompts/sent/tailwindcss-v3.txt (3,739 bytes, md5 f44aeae2d3a5b4998eec53b3b3aa93d3), concurrently with and blind to `v5-a`, after the pre-registration was pushed at 6c4b785. Identity from the probe run before both draws, same alias, same session: Opus 5.5, `claude-opus-5-5[1m]`, June 2026, all three from its system prompt. The BLIND TWIN, pre-registered as non-charging. DISCLOSED: the operator of this studio runs on the same model (`test.self_test`).",
    "self_reported_cutoff": "2026-06",
    "cutoff_basis": "Self-reported and AFFIRMING at direct (b): \"My stated training cutoff is June 2026. My reliable knowledge of Tailwind releases thins out well before that, around mid-2025.\" A recall-density qualification, not a substitute date.",
    "believed_latest_version": "4.1.x",
    "believed_latest_quote": "\"The latest version I know of is the v4.1.x line. I have a vague sense that a v4.2 may exist, but I can't confirm it. The most recent release whose contents I can actually describe is v4.1, which shipped around April 2025.\" … \"The first release I know only as a version number is **v4.2**. I believe it exists, but I can't describe its contents with any confidence.\"",
    "believed_latest_quote_form": "draw",
    "knowledge_stops_at_version": "4.1.0",
    "knowledge_stops_on": "2025-04-01",
    "knowledge_stops_provenance": "stated",
    "knowledge_gap_starts_at_version": "4.2.0",
    "knowledge_gap_starts_on": "2026-02-18",
    "knowledge_gap_provenance": "stated",
    "boundary_note": "Identical to `v5-a` and to this subject's ladder `tailwindcss/v4`. Its 4.1 description matches theirs item for item. No 4.2.0 or 4.3.0 content anywhere in the reply; the stated end is clean.",
    "cutoff_lag_months": 14
  },
  "test": {
    "date": "2026-09-27",
    "battery": "tailwindcss/v5-b",
    "battery_spec": "prompts/tailwindcss.md",
    "prompt_file": "prompts/sent/tailwindcss-v3.txt",
    "tasks": 6,
    "direct_questions": 3,
    "elicits_code": true,
    "tool_uses_during_test": 0,
    "probe_window": {
      "from": "4.3.0",
      "to": "4.3.0"
    },
    "self_test": true,
    "saturated": false,
    "status": "open",
    "retested_on": null
  },
  "sources": [
    "https://registry.npmjs.org/tailwindcss",
    "https://github.com/tailwindlabs/tailwindcss/releases/tag/v4.3.0",
    "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.2.0.tgz",
    "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.3.3.tgz"
  ],
  "findings": [],
  "non_findings": [
    {
      "kind": "miss",
      "summary": "TASK 1(a) \"No\" (\"stock Tailwind v4 has no first-class `scrollbar-width`, `scrollbar-color` or `scrollbar-gutter` utilities. Those class names come from the third-party `tailwind-scrollbar` plugin\"), and task 3: \"none of these exist in core. They are plugin classes, and without the plugin they generate nothing.\" Same denial and same review rejection as the charging twin, on a release inside this draw's stated window.",
      "api": "scrollbar-auto / scrollbar-thin / scrollbar-none / scrollbar-thumb-* / scrollbar-track-* / scrollbar-gutter-*",
      "introduced_in": "4.3.0",
      "chargeable_miss": true,
      "miss_class": "non_charging_arm",
      "charged_on": "tailwindcss--claude-opus-5-5--v5-a--2026-09-27",
      "why_not_a_finding": "The blind twin, pre-registered as non-charging before either draw returned. The same failure is charged as F1 on `v5-a`."
    },
    {
      "kind": "miss",
      "summary": "TASK 3: \"`tab-4`: not in core as far as I know. Write `[tab-size:4]`.\" and \"`zoom-50`: not in core as far as I know. Write `[zoom:0.5]`, or `scale-50` if a transform is what's actually wanted.\" Both classes compile at 4.3.0 and 4.3.3; both replacements compile too.",
      "api": "zoom-* / tab-*",
      "introduced_in": "4.3.0",
      "chargeable_miss": true,
      "miss_class": "non_charging_arm",
      "charged_on": "tailwindcss--claude-opus-5-5--v5-a--2026-09-27",
      "why_not_a_finding": "Non-charging arm. Charged as F2 on `v5-a`."
    },
    {
      "kind": "miss",
      "summary": "TASK 4(a) \"No\": \"`@variant` takes a single variant. I'm not confident whether stacked syntax like `@variant hover:focus` works, so I wouldn't ship it.\" Nested `@variant hover { @variant focus { … } }` for the AND, plain `&:hover, &:focus, &:active` for the OR. It then noted, correctly, that `@variant hover` wraps the block in `@media (hover: hover)` while the plain selector does not — verified in the compiled output at 4.2.0 and 4.3.x — so its OR block is not quite the same rule as `@variant hover, focus, active`, and it said so.",
      "api": "@variant (stacked and compound variants)",
      "introduced_in": "4.3.0",
      "chargeable_miss": true,
      "miss_class": "non_charging_arm",
      "charged_on": "tailwindcss--claude-opus-5-5--v5-a--2026-09-27",
      "why_not_a_finding": "Non-charging arm. Charged as F3 on `v5-a`."
    },
    {
      "kind": "context",
      "summary": "TASK 3, `@container-size`: an abstention, as on the charging twin, not charged there either. \"I'm unsure. I know `@container` (inline-size) and `@container-normal`. I don't have a confident memory of `@container-size` existing. If it doesn't, write `[container-type:size]`.\" This twin leans the other way from `v5-a` (\"no confident memory of it existing\" against \"a vague memory that a size variant was added\") but neither says the class generates nothing.",
      "api": "@container-size",
      "introduced_in": "4.3.0"
    },
    {
      "kind": "correct",
      "summary": "TASK 2, the internal guessing control: no invention. \"The framework does not cover this. Standard CSS doesn't either: `scrollbar-color` only takes a thumb colour and a track colour, with no corner value.\" Shipped `[&::-webkit-scrollbar-corner]:bg-slate-100`, which compiles at 4.2.0, 4.3.0 and 4.3.3.",
      "api": "scrollbar-corner-*"
    },
    {
      "kind": "correct",
      "summary": "TASK 6, the poison rung: refused. \"I don't know of one. I have no knowledge of a release adding `overflow-anchor` utilities. Use `[overflow-anchor:none]`.\"",
      "api": "overflow-anchor"
    },
    {
      "kind": "context",
      "summary": "BOUNDARY, identical to the twin and to the ladder: 4.1.0 described, 4.2 held as a number only, stated cutoff 2026-06. The Opus 5.5 pair agrees with itself on every probe in the battery; Fable 5.1's pair on the same bytes split once (`tab-4`)."
    }
  ],
  "open_questions": [],
  "summary": "The blind twin, charging nothing by pre-registration, and it reproduces its sibling on every probe: \"No\" to both verdict-first questions, the same five classes rejected in the task 3 review (four scrollbar utilities, `tab-4`, `zoom-50`), the same abstention on `@container-size`, no invented scrollbar-corner utility, the poison rung refused, and the same boundary at 4.1.0 with 4.2 known only as a number. Every workaround it offered compiles at 4.2.0, 4.3.0 and 4.3.3. Where Fable 5.1's pair on the same prompt split on one class, this pair did not split at all."
}