Publish benchmark task data

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Pooria Arab
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+---
+license: "mit"
+language:
+- en
+pretty_name: "Accessibility Fix"
+tags:
+- benchmark
+- llm-evaluation
+- ai-benchmark
+- model-evaluation
+- evals
+- grading
+- accessibility
+- a11y
+- wcag
+- openrouter
+- openai
+- mcp
+- typescript
+- agent-benchmark
+task_categories:
+- text-generation
+size_categories:
+- n<1K
+configs:
+- config_name: default
+  data_files:
+  - split: test
+    path: data/tasks.jsonl
+---
+
+# Accessibility Fix
+
+Fix a broken page so keyboard, screen-reader and contrast checks pass.
+
+## What it measures
+
+Whether a fixed HTML page really repairs injected keyboard, screen-reader, and contrast defects without deleting or hiding content.
+
+Category: `coding`. Status: `alpha`.
+
+## How to run
+
+```console
+$ npx benchmark-accessibility-fix list
+$ npx benchmark-accessibility-fix run --model <model-id> --provider openrouter
+$ npx benchmark-accessibility-fix score results.json
+```
+
+`--provider mock` runs the whole benchmark offline with no keys. Real models run
+through OpenRouter (`OPENROUTER_API_KEY`) or any OpenAI-compatible base URL
+(`OPENAI_BASE_URL`, `OPENAI_API_KEY`).
+
+## Data fields
+
+`data/tasks.jsonl` holds 40 tasks, one JSON object per line
+(kinds: 40 single).
+
+| field | type |
+|---|---|
+| `id` | string |
+| `kind` | string |
+| `prompt` | string |
+| `expected` | string |
+| `metadata` | object |
+
+## Provenance
+
+# Accessibility Fix provenance
+
+This file is generated from the benchmark definition.
+
+## Synthetic accessibility fixtures
+
+- Kind: `synthetic`
+- URL: https://github.com/pooriaarab/benchmark-accessibility-fix/blob/main/scripts/gen-tasks.mjs
+- Licence: `MIT`
+- Retrieved: 2026-10-16T00:00:00.000Z
+- How to get it: Run `npm run generate:tasks` (or `node scripts/gen-tasks.mjs --seed 20261015` after `npm run build`) from the repository root. The generator grades every reference page with the built package and re-draws until it scores 1. A hidden split uses another seed: `node scripts/gen-tasks.mjs --seed <n> --split hidden --out <path>`; hidden files use a11yh- ids and stay out of git and npm.
+- Contamination notes: Public tasks use seed 20261015. Treat them as possibly in training data; use a separately seeded hidden split for final comparisons.
+- Refresh: Change the seed, run the generator, and review the JSONL diff.
+
+
+## Grader
+
+Deterministic static analysis of the fixed HTML: ten WCAG-cited checks score defects fixed, minus regressions, content loss, element removal, and hiding abuse. Model judging is off.
+
+## Limitations
+
+This dataset contains only the public task split (40 tasks).
+Hidden evaluation splits use a private seed and are deliberately not part of
+this dataset. Source kinds: synthetic. These are evaluation prompts
+for the `benchmark-accessibility-fix` benchmark, not training data; scoring requires the package's
+deterministic grader. See PROVENANCE.md for contamination notes.
+
+## Citation
+
+```bibtex
+@misc{benchmark_accessibility_fix,
+  author = {Pooria Arab},
+  title = {Accessibility Fix task data},
+  year = {2026},
+  url = {https://github.com/pooriaarab/benchmark-accessibility-fix}
+}
+```
+
+## Links
+
+- npm: https://www.npmjs.com/package/benchmark-accessibility-fix
+- GitHub: https://github.com/pooriaarab/benchmark-accessibility-fix
+- Leaderboard: https://aibenchmarkindex.com/benchmarks/benchmark-accessibility-fix
+- Dataset: https://huggingface.co/datasets/pooria/benchmark-accessibility-fix

croissant.json

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+{
+  "@context": {
+    "@language": "en",
+    "@vocab": "https://schema.org/",
+    "citeAs": "cr:citeAs",
+    "column": "cr:column",
+    "conformsTo": "dct:conformsTo",
+    "cr": "http://mlcommons.org/croissant/",
+    "data": {
+      "@id": "cr:data",
+      "@type": "@json"
+    },
+    "dataBiases": "cr:dataBiases",
+    "dataCollection": "cr:dataCollection",
+    "dataType": {
+      "@id": "cr:dataType",
+      "@type": "@vocab"
+    },
+    "dct": "http://purl.org/dc/terms/",
+    "equivalentProperty": "cr:equivalentProperty",
+    "examples": {
+      "@id": "cr:examples",
+      "@type": "@json"
+    },
+    "extract": "cr:extract",
+    "field": "cr:field",
+    "fileProperty": "cr:fileProperty",
+    "fileObject": "cr:fileObject",
+    "fileSet": "cr:fileSet",
+    "format": "cr:format",
+    "includes": "cr:includes",
+    "isLiveDataset": "cr:isLiveDataset",
+    "jsonPath": "cr:jsonPath",
+    "key": "cr:key",
+    "md5": "cr:md5",
+    "parentField": "cr:parentField",
+    "path": "cr:path",
+    "personalSensitiveInformation": "cr:personalSensitiveInformation",
+    "prov": "http://www.w3.org/ns/prov#",
+    "rai": "http://mlcommons.org/croissant/RAI/",
+    "recordSet": "cr:recordSet",
+    "references": "cr:references",
+    "regex": "cr:regex",
+    "repeated": "cr:repeated",
+    "replace": "cr:replace",
+    "samplingRate": "cr:samplingRate",
+    "sc": "https://schema.org/",
+    "separator": "cr:separator",
+    "source": "cr:source",
+    "subField": "cr:subField",
+    "transform": "cr:transform"
+  },
+  "@type": "sc:Dataset",
+  "conformsTo": [
+    "http://mlcommons.org/croissant/1.0",
+    "http://mlcommons.org/croissant/RAI/1.0"
+  ],
+  "name": "Accessibility Fix",
+  "description": "Fix a broken page so keyboard, screen-reader and contrast checks pass.",
+  "url": "https://huggingface.co/datasets/pooria/benchmark-accessibility-fix",
+  "sameAs": [
+    "https://github.com/pooriaarab/benchmark-accessibility-fix",
+    "https://aibenchmarkindex.com/benchmarks/benchmark-accessibility-fix"
+  ],
+  "license": "https://choosealicense.com/licenses/mit/",
+  "creator": {
+    "@type": "Person",
+    "name": "Pooria Arab",
+    "url": "https://github.com/pooriaarab"
+  },
+  "datePublished": "2026-10-16",
+  "dateModified": "2026-10-16",
+  "version": "0.1.0",
+  "inLanguage": "en",
+  "keywords": [
+    "benchmark-accessibility-fix",
+    "llm-evaluation",
+    "benchmark"
+  ],
+  "isAccessibleForFree": true,
+  "citeAs": "@misc{benchmark-accessibility-fix, author={Pooria Arab}, title={Accessibility Fix}, year={2026}, url={https://github.com/pooriaarab/benchmark-accessibility-fix}}",
+  "distribution": [
+    {
+      "@type": "cr:FileObject",
+      "@id": "data/PROVENANCE.md",
+      "name": "data/PROVENANCE.md",
+      "contentUrl": "https://huggingface.co/datasets/pooria/benchmark-accessibility-fix/resolve/main/data/PROVENANCE.md",
+      "encodingFormat": "text/markdown",
+      "sha256": "6f952aa73169afa78d3ac72269bcec7e2136b77b27d6f8b0caa5b42da13df958"
+    },
+    {
+      "@type": "cr:FileObject",
+      "@id": "data/tasks.jsonl",
+      "name": "data/tasks.jsonl",
+      "contentUrl": "https://huggingface.co/datasets/pooria/benchmark-accessibility-fix/resolve/main/data/tasks.jsonl",
+      "encodingFormat": "application/jsonlines",
+      "sha256": "20d9f94a23dfa0d137e1235d84e3981b358ec54b0dd9d48ad4bba052cd207cc8"
+    },
+    {
+      "@type": "cr:FileObject",
+      "@id": "scripts/gen-tasks.mjs",
+      "name": "scripts/gen-tasks.mjs",
+      "contentUrl": "https://huggingface.co/datasets/pooria/benchmark-accessibility-fix/resolve/main/scripts/gen-tasks.mjs",
+      "encodingFormat": "text/javascript",
+      "sha256": "fb61fec6a1ca75c7bc92e9a6908c0352d3b1617c728ecf762446302f0b10e45e"
+    },
+    {
+      "@type": "cr:FileObject",
+      "@id": "LICENSE",
+      "name": "LICENSE",
+      "contentUrl": "https://huggingface.co/datasets/pooria/benchmark-accessibility-fix/resolve/main/LICENSE",
+      "encodingFormat": "text/plain",
+      "sha256": "db83f2db2a2b6a3b5587ce4750a3a6cff3dd1219650fa1ea3b3354ee04891d96"
+    }
+  ],
+  "recordSet": [
+    {
+      "@type": "cr:RecordSet",
+      "name": "tasks",
+      "description": "40 benchmark tasks, one JSON object per line.",
+      "field": [
+        {
+          "@type": "cr:Field",
+          "name": "id",
+          "dataType": "sc:Text",
+          "source": {
+            "fileObject": {
+              "@id": "data/tasks.jsonl"
+            },
+            "extract": {
+              "jsonPath": "$.id"
+            }
+          }
+        },
+        {
+          "@type": "cr:Field",
+          "name": "kind",
+          "dataType": "sc:Text",
+          "source": {
+            "fileObject": {
+              "@id": "data/tasks.jsonl"
+            },
+            "extract": {
+              "jsonPath": "$.kind"
+            }
+          }
+        },
+        {
+          "@type": "cr:Field",
+          "name": "prompt",
+          "dataType": "sc:Text",
+          "source": {
+            "fileObject": {
+              "@id": "data/tasks.jsonl"
+            },
+            "extract": {
+              "jsonPath": "$.prompt"
+            }
+          }
+        },
+        {
+          "@type": "cr:Field",
+          "name": "expected",
+          "dataType": "sc:Text",
+          "source": {
+            "fileObject": {
+              "@id": "data/tasks.jsonl"
+            },
+            "extract": {
+              "jsonPath": "$.expected"
+            }
+          }
+        },
+        {
+          "@type": "cr:Field",
+          "name": "metadata",
+          "dataType": "sc:Text",
+          "source": {
+            "fileObject": {
+              "@id": "data/tasks.jsonl"
+            },
+            "extract": {
+              "jsonPath": "$.metadata"
+            }
+          }
+        }
+      ]
+    }
+  ],
+  "rai:dataCollection": "Public task split cloned from the benchmark repository; tasks are produced by scripts/gen-tasks.mjs with a fixed public seed.",
+  "rai:dataCollectionType": "Benchmark task prompts for LLM evaluation.",
+  "rai:dataCollectionRawData": "https://github.com/pooriaarab/benchmark-accessibility-fix/tree/main/data",
+  "rai:dataReleaseMaintenancePlan": "Refreshed when the benchmark's public seed changes; hidden splits are generated with a private seed and never published.",
+  "rai:dataLimitations": "Public split only (40 tasks); hidden evaluation splits are held out. Evaluation prompts, not training data.",
+  "rai:dataBiases": "Synthetic task families oversample the shapes the generator enumerates; coverage of real-world variation is limited by the generator templates.",
+  "rai:personalSensitiveInformation": "None. Tasks contain no personal data; names, orders and scenarios are generated fixtures.",
+  "rai:dataUseCases": [
+    "Testing and comparing LLM/agent behaviour on the measured construct",
+    "Regression testing of model releases"
+  ],
+  "rai:dataSocialImpact": "Low risk: synthetic eval data. Improves transparency of model capability claims when used responsibly.",
+  "rai:hasSyntheticData": true,
+  "prov:wasDerivedFrom": [
+    "https://github.com/pooriaarab/benchmark-accessibility-fix/blob/main/scripts/gen-tasks.mjs"
+  ],
+  "prov:wasGeneratedBy": [
+    {
+      "@type": "prov:Activity",
+      "name": "Synthetic accessibility fixtures",
+      "description": "synthetic source: https://github.com/pooriaarab/benchmark-accessibility-fix/blob/main/scripts/gen-tasks.mjs"
+    }
+  ],
+  "alternateName": [
+    "pooria/benchmark-accessibility-fix"
+  ]
+}

data/PROVENANCE.md

@@ -0,0 +1,13 @@
+# Accessibility Fix provenance
+
+This file is generated from the benchmark definition.
+
+## Synthetic accessibility fixtures
+
+- Kind: `synthetic`
+- URL: https://github.com/pooriaarab/benchmark-accessibility-fix/blob/main/scripts/gen-tasks.mjs
+- Licence: `MIT`
+- Retrieved: 2026-10-16T00:00:00.000Z
+- How to get it: Run `npm run generate:tasks` (or `node scripts/gen-tasks.mjs --seed 20261015` after `npm run build`) from the repository root. The generator grades every reference page with the built package and re-draws until it scores 1. A hidden split uses another seed: `node scripts/gen-tasks.mjs --seed <n> --split hidden --out <path>`; hidden files use a11yh- ids and stay out of git and npm.
+- Contamination notes: Public tasks use seed 20261015. Treat them as possibly in training data; use a separately seeded hidden split for final comparisons.
+- Refresh: Change the seed, run the generator, and review the JSONL diff.

scripts/gen-tasks.mjs

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+// Generates synthetic accessibility-fix fixtures (MIT).
+// Usage: node scripts/gen-tasks.mjs [--seed N] [--split public|hidden] [--out path] [--count N]
+// Public split defaults to data/tasks.jsonl with seed 20261015.
+// Hidden split defaults to artifacts/tasks.hidden.jsonl (gitignored, never published)
+// and uses its own a11yh- id prefix so hidden ids never collide with public ones.
+import { mkdir, writeFile } from "node:fs/promises";
+import { dirname } from "node:path";
+import { createHash } from "node:crypto";
+
+const args = process.argv.slice(2);
+const get = (name, fallback) => {
+  const index = args.indexOf(name);
+  return index === -1 ? fallback : args[index + 1];
+};
+if (args.includes("--help")) {
+  console.log("Usage: node scripts/gen-tasks.mjs [--seed N] [--split public|hidden] [--out path] [--count N]");
+  process.exit(0);
+}
+const seed = Number(get("--seed", "20261015"));
+const split = get("--split", "public");
+const count = Number(get("--count", "40"));
+const out = get("--out", split === "hidden" ? "artifacts/tasks.hidden.jsonl" : "data/tasks.jsonl");
+if (!Number.isInteger(seed) || !Number.isInteger(count) || count < 1) throw new Error("seed and count must be positive integers");
+if (split !== "public" && split !== "hidden") throw new Error("--split must be public or hidden");
+
+function mulberry32(start) {
+  let state = start >>> 0;
+  return () => {
+    state += 1831565813;
+    let value = state;
+    value = Math.imul(value ^ (value >>> 15), value | 1);
+    value ^= value + Math.imul(value ^ (value >>> 7), value | 61);
+    return ((value ^ (value >>> 14)) >>> 0) / 4294967296;
+  };
+}
+
+const pick = (rng, list) => list[Math.floor(rng() * list.length)];
+const pickN = (rng, list, n) => {
+  const copy = [...list];
+  const out = [];
+  while (out.length < Math.min(n, copy.length)) out.push(copy.splice(Math.floor(rng() * copy.length), 1)[0]);
+  return out;
+};
+const shuffle = (rng, list) => {
+  const a = [...list];
+  for (let i = a.length - 1; i > 0; i--) {
+    const j = Math.floor(rng() * (i + 1));
+    [a[i], a[j]] = [a[j], a[i]];
+  }
+  return a;
+};
+
+// WCAG relative luminance for #rrggbb.
+function luminance(hex) {
+  const h = hex.replace("#", "");
+  const [r, g, b] = [0, 2, 4].map((i) => {
+    const c = parseInt(h.slice(i, i + 2), 16) / 255;
+    return c <= 0.03928 ? c / 12.92 : ((c + 0.055) / 1.055) ** 2.4;
+  });
+  return 0.2126 * r + 0.7152 * g + 0.0722 * b;
+}
+const ratio = (a, b) => {
+  const [x, y] = [luminance(a), luminance(b)].sort((m, n) => n - m);
+  return (x + 0.05) / (y + 0.05);
+};
+const hex = (rng, lo, hi) => "#" + [0, 1, 2].map(() => (lo + Math.floor(rng() * (hi - lo + 1))).toString(16).padStart(2, "0")).join("");
+
+// A passing foreground/background pair at >= minRatio. The default
+// carries margin over the 4.5:1 rule so equivalent color spellings
+// (hsl() with rounded channels, 8-digit hex) cannot dip a reference
+// page under the threshold.
+function goodPair(rng, minRatio = 4.75) {
+  for (let tries = 0; tries < 200; tries++) {
+    const bg = hex(rng, 200, 255);
+    const fg = hex(rng, 0, 120);
+    if (ratio(fg, bg) >= minRatio) return { fg, bg };
+  }
+  throw new Error("no good pair found");
+}
+// A failing pair against a fixed background (text lands in the 3.5-4.4 band
+// so the defect is visible but not blatant).
+function badFg(rng, bg) {
+  for (let tries = 0; tries < 400; tries++) {
+    const fg = hex(rng, 120, 190);
+    const r = ratio(fg, bg);
+    if (r < 4.5 && r > 2.5) return fg;
+  }
+  return "#8a8a8a";
+}
+// A passing foreground on a FIXED background: the inline span inherits
+// the body background, so it must be drawn against it, not against a
+// throwaway pair bg.
+function goodFg(rng, bg, minRatio = 4.75) {
+  for (let tries = 0; tries < 400; tries++) {
+    const fg = hex(rng, 0, 130);
+    if (ratio(fg, bg) >= minRatio) return fg;
+  }
+  throw new Error("no good foreground found");
+}
+// A large-text pair in the passing 3:1-4.5 band (valid fix, tests the
+// large-text threshold). The 3.3 floor leaves room for color-format
+// rounding noise, same margin idea as goodPair.
+function largePair(rng) {
+  for (let tries = 0; tries < 300; tries++) {
+    const bg = hex(rng, 200, 255);
+    const fg = hex(rng, 60, 160);
+    const r = ratio(fg, bg);
+    if (r >= 3.3 && r < 4.5) return { fg, bg };
+  }
+  throw new Error("no large pair found");
+}
+
+const CHECKS = [
+  ["missing-alt", "1.1.1"], ["unlabeled-input", "3.3.2"], ["low-contrast", "1.4.3"],
+  ["heading-order", "1.3.1"], ["tabindex-positive", "2.4.3"], ["div-button", "4.1.2"],
+  ["missing-lang", "3.1.1"], ["no-focus-style", "2.4.7"], ["empty-link", "2.4.4"],
+  ["table-headers", "1.3.1"],
+];
+const WCAG = Object.fromEntries(CHECKS);
+
+const ADJ = ["Harbor", "Kestrel", "Northern", "River", "Garden", "Amber", "Cedar", "Juniper", "Misty", "Copper", "Silver", "Quiet", "Bright", "Willow", "Frost", "Ember", "Sage", "Coral", "Atlas", "Meadow"];
+const NOUN = ["Lights", "Ridge", "Valley", "Crossing", "Mills", "Works", "Foundry", "Collective", "Cooperative", "Observatory", "Pantry", "Workshop", "Ledger", "Orchard", "Depot", "Exchange", "Studio", "Clinic", "Archive", "Guild"];
+const KIND = ["newsletter", "field guide", "status report", "release notes", "handbook", "bulletin", "weekly digest", "product sheet", "setup guide", "survey results", "booking page", "service page"];
+const TOPICS = [
+  ["ferry sailings", "harbor notes", "crossing times"],
+  ["grind settings", "care notes", "brew ratios"],
+  ["sleeper bookings", "reading list", "departure board"],
+  ["volunteer shifts", "meeting point", "supply list"],
+  ["api keys", "rate limits", "endpoint status"],
+  ["survey findings", "next steps", "member quotes"],
+  ["trail conditions", "permit windows", "ranger notes"],
+  ["menu changes", "supplier list", "order cutoffs"],
+  ["rehearsal dates", "set list", "venue notes"],
+  ["seed inventory", "planting calendar", "pest watch"],
+  ["loan rates", "branch hours", "member news"],
+  ["build artifacts", "test matrix", "deploy log"],
+];
+const NOTES = [
+  "New routes post every Sunday evening.", "Burrs carry a five year warranty.",
+  "Berths sell out around holidays.", "Gloves and bags are provided.",
+  "Keys rotate every ninety days.", "Two hundred members answered.",
+  "Permits open on the first Monday.", "Orders close at noon on Fridays.",
+  "Rehearsals move indoors in winter.", "Seed counts refresh monthly.",
+  "Rates lock for sixty days.", "Artifacts prune after thirty days.",
+];
+const SPANS = [
+  "Ferries run hourly on holidays.", "Free returns within thirty days.",
+  "Bring a lock for the cabin door.", "All ages welcome with an adult.",
+  "Sandbox data refreshes hourly.", "Evening hours were the top ask.",
+  "Boots are required past the gate.", "Late orders ship the next day.",
+  "Guests may watch the last set.", "Cover beds before a frost.",
+  "Statements arrive by post.", "Flaky tests quarantine on retry.",
+];
+const ALTS = [
+  "Ferry crossing the harbor at dusk", "Steel burr coffee grinder on a counter",
+  "Sleeper train under northern lights", "Volunteers clearing a riverbank",
+  "Soil sensor beside tomato plants", "Reading room with tall shelves",
+  "Trail marker above the treeline", "Stacked crates at the loading dock",
+  "String section tuning on stage", "Seed packets on a potting bench",
+  "Teller counter at the main branch", "Build monitor showing green jobs",
+];
+const CTA = ["Subscribe", "Add to basket", "Save article", "Join us", "Get a key", "Download PDF", "Book now", "Reserve a spot", "Notify me", "Start trial"];
+const NAV2 = ["About", "FAQ", "Pricing", "News", "Docs", "Team", "Contact", "Archive"];
+const FIELD_POOL = [
+  ["name", "Full name", "text"], ["email", "Email address", "email"],
+  ["phone", "Phone number", "tel"], ["org", "Organization", "text"],
+  ["city", "City", "text"], ["note", "Delivery note", "text"],
+];
+const CLASS_A = ["note", "hint", "aside", "fine", "meta", "muted"];
+const CLASS_B = ["cta", "btn-primary", "action", "primary-btn", "main-action", "go"];
+const CAPTIONS = ["Crossing times", "Grind guide", "Departure board", "Cleanup shifts", "Endpoint limits", "Survey results", "Permit windows", "Order ledger", "Rehearsal slots", "Seed counts", "Rate sheet", "Build history"];
+const COLHEADS = [["Option", "Detail", "Status"], ["Name", "Owner", "State"], ["Step", "Input", "Output"], ["Item", "Count", "Flag"]];
+const CELLS = [["Standard", "Weekly", "Open"], ["Plus", "Daily", "Open"], ["Rush", "Hourly", "Full"], ["Basic", "Monthly", "Closed"], ["Trial", "Once", "Open"], ["Custom", "On call", "Open"]];
+
+// One randomized but fully accessible page. Returns the HTML plus a hooks
+// object with the exact strings defect breakers can target.
+function buildFixed(rng) {
+  const title = `${pick(rng, ADJ)} ${pick(rng, NOUN)} ${pick(rng, KIND)}`;
+  const topics = pick(rng, TOPICS);
+  const [h2a, h2b, caption] = [topics[0], topics[1], pick(rng, CAPTIONS)];
+  const noteClass = pick(rng, CLASS_A);
+  const ctaClass = pick(rng, CLASS_B);
+  const noteText = pick(rng, NOTES);
+  const spanText = pick(rng, SPANS);
+  const heroAlt = pick(rng, ALTS);
+  const img = `https://example.com/${title.toLowerCase().replace(/[^a-z]+/g, "-")}.jpg`;
+  const ctaText = pick(rng, CTA);
+  const nav2 = pick(rng, NAV2);
+  const fields = pickN(rng, FIELD_POOL, 2 + Math.floor(rng() * 2));
+  const colheads = pick(rng, COLHEADS);
+  const rows = pickN(rng, CELLS, 2 + Math.floor(rng() * 2));
+  // Colors: every pair is generated to pass.
+  const body = goodPair(rng);
+  const note = goodPair(rng);
+  const spanFg = goodFg(rng, body.bg);
+  const cta = goodPair(rng);
+  const focusColor = goodPair(rng).fg;
+  // A large-text heading pair in the legal 3:1-4.5 band keeps the
+  // large-text path exercised without tripping the defect check.
+  const large = rng() < 0.5 ? largePair(rng) : null;
+  const largeRule = large ? `\n.big-head{color:${large.fg};background-color:${large.bg};font-size:26px;font-weight:700}` : "";
+  const bigHead = large ? `<h2 class="big-head">${h2a}</h2>` : `<h2>${h2a}</h2>`;
+  const styleBlock = `<style>
+body{color:${body.fg};background-color:${body.bg};font-family:system-ui,sans-serif;line-height:1.5}
+.${noteClass}{color:${note.fg};background-color:${note.bg}}
+.${ctaClass}{color:${cta.fg};background-color:${cta.bg};padding:.6rem 1rem;border:0;border-radius:.4rem}
+a:focus-visible,.${ctaClass}:focus-visible{outline:3px solid ${focusColor};outline-offset:2px}${largeRule}
+</style>`;
+
+  const skip = `<a href="#main">Skip to content</a>`;
+  const formFields = fields.map(([id, label, type]) =>
+    `<label for="${id}">${label}</label>\n<input id="${id}" name="${id}" type="${type}" autocomplete="${id}">`).join("\n");
+  const tableRows = rows.map((r) => `<tr>${r.map((c) => `<td>${c}</td>`).join("")}</tr>`).join("\n");
+  const table = `<table>\n<caption>${caption}</caption>\n<tr>${colheads.map((c) => `<th scope="col">${c}</th>`).join("")}</tr>\n${tableRows}\n</table>`;
+  const sections = shuffle(rng, [
+    `<img src="${img}" alt="${heroAlt}">`,
+    `<p class="${noteClass}">${noteText}</p>`,
+    `<p><span style="color:${spanFg}">${spanText}</span></p>`,
+    table,
+  ]);
+  const html = `<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>${title}</title>
+${styleBlock}
+</head>
+<body>
+<header>
+<nav>${skip} <a href="/${nav2.toLowerCase()}">${nav2}</a></nav>
+<h1>${title}</h1>
+</header>
+<main id="main">
+${bigHead}
+${sections[0]}
+${sections[1]}
+<h3>${h2b}</h3>
+<form action="/signup" method="post">
+${formFields}
+<button type="submit">Sign up</button>
+</form>
+${sections[2]}
+<p><button class="${ctaClass}" type="button">${ctaText}</button></p>
+${sections[3]}
+</main>
+<footer>
+<p><a href="/archive">Archive</a> <a href="/contact">Contact</a></p>
+</footer>
+</body>
+</html>`;
+  return {
+    html,
+    hooks: {
+      heroAlt: ` alt="${heroAlt}"`,
+      label: fields[1] ? `<label for="${fields[1][0]}">${fields[1][1]}</label>\n` : `<label for="${fields[0][0]}">${fields[0][1]}</label>\n`,
+      noteRule: `.${noteClass}{color:${note.fg};`,
+      noteBad: `.${noteClass}{color:${badFg(rng, note.bg)};`,
+      spanRule: `<span style="color:${spanFg}">`,
+      spanBad: `<span style="color:${badFg(rng, body.bg)}">`,
+      ctaButton: `<button class="${ctaClass}" type="button">${ctaText}</button>`,
+      ctaText,
+      focusRule: `\na:focus-visible,.${ctaClass}:focus-visible{outline:3px solid ${focusColor};outline-offset:2px}`,
+      skip,
+      archive: `<a href="/archive">Archive</a>`,
+    },
+  };
+}
+
+const TABS = ["Overview", "History", "Members", "Billing", "Usage", "Alerts", "Archive", "Notes"];
+
+// Hard tier: a different page skeleton, not the easy page with extra
+// defects. Grouped fields carry names through an aria-labelledby chain,
+// a tab widget holds role/tabindex/handler parts, and the table spans
+// headers across columns and rows - so a fixer tuned to the easy template
+// leaves real barriers behind.
+function buildHard(rng) {
+  const title = `${pick(rng, ADJ)} ${pick(rng, NOUN)} ${pick(rng, KIND)}`;
+  const topics = pick(rng, TOPICS);
+  const [h2a, h2b, h3c] = topics;
+  const caption = pick(rng, CAPTIONS);
+  const noteClass = pick(rng, CLASS_A);
+  const ctaClass = pick(rng, CLASS_B);
+  const noteText = pick(rng, NOTES);
+  const spanText = pick(rng, SPANS);
+  const heroAlt = pick(rng, ALTS);
+  const img = `https://example.com/${title.toLowerCase().replace(/[^a-z]+/g, "-")}.jpg`;
+  const ctaText = pick(rng, CTA);
+  const nav2 = pick(rng, NAV2);
+  const cardText = pick(rng, CTA.filter((c) => c !== ctaText));
+  const tabs = pickN(rng, TABS, 2);
+  const [f0, f1, f2] = pickN(rng, FIELD_POOL, 3);
+  const colheads = pick(rng, COLHEADS);
+  const cells = pickN(rng, CELLS, 4);
+  const body = goodPair(rng);
+  const note = goodPair(rng);
+  const spanFg = goodFg(rng, body.bg);
+  const cta = goodPair(rng);
+  const tabPair = goodPair(rng);
+  const focusColor = goodPair(rng).fg;
+  const large = rng() < 0.5 ? largePair(rng) : null;
+  const largeRule = large ? `\n.big-head{color:${large.fg};background-color:${large.bg};font-size:26px;font-weight:700}` : "";
+  const bigHead = large ? `<h2 class="big-head" id="deck">${h2a}</h2>` : `<h2 id="deck">${h2a}</h2>`;
+  const styleBlock = `<style>
+body{color:${body.fg};background-color:${body.bg};font-family:system-ui,sans-serif;line-height:1.5}
+.${noteClass}{color:${note.fg};background-color:${note.bg}}
+.tab{color:${tabPair.fg};background-color:${tabPair.bg};padding:.4rem .8rem;display:inline-block}
+.${ctaClass}{color:${cta.fg};background-color:${cta.bg};padding:.6rem 1rem;border:0;border-radius:.4rem}
+a:focus-visible,.${ctaClass}:focus-visible,[role=tab]:focus-visible{outline:3px solid ${focusColor};outline-offset:2px}${largeRule}
+</style>`;
+
+  const skip = `<a href="#main">Skip to content</a>`;
+  const labelParts = f0[1].split(" ");
+  const labSpanA = `<span id="l-a">${labelParts[0]}</span>`;
+  const labSpanB = `<span id="l-b">${labelParts.slice(1).join(" ") || pick(rng, topics)}</span>`;
+  const tabA = `<div role="tab" tabindex="0" onkeydown="pickTab('a')" aria-selected="true">${tabs[0]}</div>`;
+  const tabB = `<div role="tab" tabindex="0" onkeydown="pickTab('b')" aria-selected="false">${tabs[1]}</div>`;
+  const tabsOpen = `<div class="tabs" role="tablist" aria-labelledby="tabs-title">`;
+  const label = `<label for="hf2">${f1[1]}</label>`;
+  const cardHref = `/${cardText.toLowerCase().replace(/[^a-z0-9]+/g, "-")}`;
+  const cardLink = `<a href="${cardHref}">${cardText}</a>`;
+  const table = `<table>
+<caption>${caption}</caption>
+<tr><th scope="col">${colheads[0]}</th><th colspan="2" scope="colgroup">${colheads[1]}</th></tr>
+<tr><th scope="row">${cells[0][0]}</th><td>${cells[0][1]}</td><td>${cells[0][2]}</td></tr>
+<tr><th scope="row">${cells[1][0]}</th><td>${cells[1][1]}</td><td>${cells[1][2]}</td></tr>
+<tr><th scope="row">${cells[2][0]}</th><td>${cells[2][1]}</td><td>${cells[2][2]}</td></tr>
+</table>`;
+  const sections = shuffle(rng, [
+    `<img src="${img}" alt="${heroAlt}">`,
+    `<p class="${noteClass}">${noteText}</p>`,
+    `<p><span style="color:${spanFg}">${spanText}</span></p>`,
+    table,
+  ]);
+  const html = `<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>${title}</title>
+${styleBlock}
+</head>
+<body>
+<header>
+<nav>${skip} <a href="/${nav2.toLowerCase()}">${nav2}</a></nav>
+<h1>${title}</h1>
+</header>
+<main id="main">
+${bigHead}
+<section aria-labelledby="deck">
+${sections[0]}
+${sections[1]}
+</section>
+<h3 id="tabs-title">${h2b}</h3>
+${tabsOpen}
+${tabA}
+${tabB}
+</div>
+<h4>${h3c}</h4>
+<fieldset>
+<legend>${h3c}</legend>
+${labSpanA} ${labSpanB}
+<input id="hf1" name="hf1" type="${f0[2]}" autocomplete="off" aria-labelledby="l-a l-b">
+${label}
+<input id="hf2" name="hf2" type="${f1[2]}" autocomplete="${f1[0]}">
+<input id="hf3" name="hf3" type="${f2[2]}" autocomplete="${f2[0]}" aria-label="${f2[1]}">
+</fieldset>
+${sections[2]}
+<p>${cardLink} <button class="${ctaClass}" type="button">${ctaText}</button></p>
+${sections[3]}
+</main>
+<footer>
+<p><a href="/archive">Archive</a> <a href="/contact">Contact</a></p>
+</footer>
+</body>
+</html>`;
+  return {
+    html,
+    hooks: {
+      heroAlt: ` alt="${heroAlt}"`,
+      label: `${label}\n`,
+      labSpanA,
+      labSpanB,
+      labelledby: `aria-labelledby="l-a l-b"`,
+      noteRule: `.${noteClass}{color:${note.fg};`,
+      noteBad: `.${noteClass}{color:${badFg(rng, note.bg)};`,
+      spanRule: `<span style="color:${spanFg}">`,
+      spanBad: `<span style="color:${badFg(rng, body.bg)}">`,
+      tabA,
+      tabsOpen,
+      ctaButton: `<button class="${ctaClass}" type="button">${ctaText}</button>`,
+      ctaText,
+      focusRule: `\na:focus-visible,.${ctaClass}:focus-visible,[role=tab]:focus-visible{outline:3px solid ${focusColor};outline-offset:2px}`,
+      skip,
+      archive: `<a href="/archive">Archive</a>`,
+      cardLink,
+      cardHref,
+      cardText,
+      heading3: `<h3 id="tabs-title">${h2b}</h3>`,
+    },
+  };
+}
+
+// Each breaker rewrites one hook in the fixed page. Variants make the same
+// defect appear in different disguises (role-button lookalikes, multi-step
+// tab order, empty-label silences) so a template-aware regex fixer misses.
+const BREAKERS = {
+  "missing-alt": (h) => [(p) => p.replace(h.hooks.heroAlt, ""), "alt removed"],
+  "unlabeled-input": (h, rng) => {
+    const variant = rng();
+    if (variant < 0.5) return [(p) => p.replace(h.hooks.label, ""), "label removed"];
+    if (variant < 0.8) return [(p) => p.replace(/<label for="(\w+)">/, '<label for="missing-$1">'), "label for broken"];
+    return [(p) => p.replace(h.hooks.label.trimEnd(), h.hooks.label.trimEnd().replace(/>([^<]+)</, "><")), "label emptied"];
+  },
+  "low-contrast": (h) => [(p) => p.replace(h.hooks.noteRule, h.hooks.noteBad).replace(h.hooks.spanRule, h.hooks.spanBad), "colors dimmed"],
+  "heading-order": (h, rng) => [(p) => (rng() < 0.5
+    ? p.replace("<h3>", "<h5>").replace("</h3>", "</h5>")
+    : p.replace("<h1>", "<h2>").replace("</h1>", "</h2>")), "headings shuffled"],
+  "tabindex-positive": (h, rng) => [(p) => {
+    // Multi-step order: sprinkle 1-3 positive tabindices across the page.
+    let out = p.replace('<a href="#main">', '<a tabindex="3" href="#main">');
+    if (rng() < 0.6) out = out.replace('<a href="/archive">', '<a tabindex="1" href="/archive">');
+    if (rng() < 0.4) out = out.replace('type="submit"', 'tabindex="7" type="submit"');
+    return out;
+  }, "tabindex added"],
+  "div-button": (h, rng) => {
+    const v = rng();
+    const repl = v < 0.4
+      ? `<div class="cta-div" onclick="go()">${h.hooks.ctaText}</div>`
+      : v < 0.7
+        ? `<div role="button">${h.hooks.ctaText}</div>`
+        : `<span class="cta-div" onclick="go()">${h.hooks.ctaText}</span>`;
+    return [(p) => p.replace(h.hooks.ctaButton, repl), "button divved"];
+  },
+  "missing-lang": () => [(p) => p.replace('<html lang="en">', "<html>"), "lang removed"],
+  "no-focus-style": (h) => [(p) => p.replace(h.hooks.focusRule, ""), "focus rule removed"],
+  "empty-link": (h, rng) => {
+    const v = rng();
+    if (v < 0.5) return [(p) => p.replace(h.hooks.archive, '<a href="/archive"></a>'), "link emptied"];
+    if (v < 0.8) return [(p) => p.replace(h.hooks.archive, '<a href="/archive" aria-label=""></a>'), "link label emptied"];
+    return [(p) => p.replace(h.hooks.archive, '<a href="/archive"><span class="icon"></span></a>'), "link icon unlabeled"];
+  },
+  "table-headers": () => [(p) => p.replaceAll("<th scope=\"col\">", "<td>").replaceAll("</th>", "</td>"), "headers demoted"],
+};
+
+// Hard-tier breakers hit the widget skeleton: dangling name chains, a Tab
+// trap, a control nested in a link, a widget hidden from AT, and spanning
+// headers demoted. Each leaves the page looking close to fixed, so a
+// template-aware repair still fails the check.
+const HARD_BREAKERS = {
+  "missing-alt": (h) => [(p) => p.replace(h.hooks.heroAlt, ""), "alt removed"],
+  "unlabeled-input": (h, rng) => {
+    const v = rng();
+    if (v < 0.35) return [(p) => p.replace(h.hooks.labSpanB, h.hooks.labSpanB.replace('id="l-b"', 'id="l-gone"')), "labelledby link cut"];
+    if (v < 0.6) return [(p) => p.replace(h.hooks.labSpanA, h.hooks.labSpanA.replace(/>([^<]+)</, "><")).replace(h.hooks.labSpanB, h.hooks.labSpanB.replace(/>([^<]+)</, "><")), "labelledby emptied"];
+    if (v < 0.8) return [(p) => p.replace(h.hooks.labelledby, 'aria-labelledby="l-a l-missing"'), "labelledby dangled"];
+    return [(p) => p.replace(h.hooks.label, ""), "label removed"];
+  },
+  "low-contrast": (h) => [(p) => p.replace(h.hooks.noteRule, h.hooks.noteBad).replace(h.hooks.spanRule, h.hooks.spanBad), "colors dimmed"],
+  "heading-order": (h, rng) => [(p) => (rng() < 0.5
+    ? p.replace("<h3", "<h5").replace("</h3>", "</h5>")
+    : p.replace("<h1>", "<h2>").replace("</h1>", "</h2>")), "headings shuffled"],
+  "tabindex-positive": (h, rng) => [(p) => {
+    // Two disguises: a focus trap on the first tab (Tab swallowed), and
+    // a bent multi-step order across nav and footer.
+    let out = p;
+    if (rng() < 0.6) out = out.replace('onkeydown="pickTab(\'a\')"', "onkeydown=\"if(event.key==='Tab')event.preventDefault()\"");
+    out = out.replace('<a href="#main">', '<a tabindex="2" href="#main">');
+    if (rng() < 0.5) out = out.replace('<a href="/archive">', '<a tabindex="1" href="/archive">');
+    return out;
+  }, "tab order bent"],
+  "div-button": (h, rng) => {
+    const v = rng();
+    if (v < 0.4) return [(p) => p.replace(`<p>${h.hooks.cardLink} ${h.hooks.ctaButton}</p>`, `<p><a href="${h.hooks.cardHref}">${h.hooks.cardText}<div class="cta-div" onclick="go()">${h.hooks.ctaText}</div></a></p>`), "control nested in link"];
+    if (v < 0.7) return [(p) => p.replace(h.hooks.tabA, h.hooks.tabA.replace(' tabindex="0" onkeydown="pickTab(\'a\')"', "")), "tab lost keyboard support"];
+    return [(p) => p.replace(h.hooks.tabsOpen, h.hooks.tabsOpen.replace(/>$/, ' aria-hidden="true">')), "widget hidden from AT"];
+  },
+  "missing-lang": () => [(p) => p.replace('<html lang="en">', "<html>"), "lang removed"],
+  "no-focus-style": (h) => [(p) => p.replace(h.hooks.focusRule, ""), "focus rule removed"],
+  "empty-link": (h, rng) => {
+    const v = rng();
+    // The div-button breaker can consume the card link first; the footer
+    // archive link is always there as a fallback target.
+    return [(p) => {
+      const target = p.includes(h.hooks.cardLink) ? h.hooks.cardLink : h.hooks.archive;
+      if (v < 0.4 && target === h.hooks.cardLink) return p.replace(target, target.replace(">", ' aria-labelledby="ghost">'));
+      if (v < 0.7) return p.replace(target, target.replace(/>([^<]+)</, "><"));
+      return p.replace(target, target.replace(/>([^<]+)</, '><span class="icon"></span><'));
+    }, "link name removed"];
+  },
+  "table-headers": () => [(p) => p.replaceAll("<th ", "<td ").replaceAll("</th>", "</td>"), "headers demoted"],
+};
+
+function pickDefects(rng, taskIndex, tier) {
+  const ids = CHECKS.map(([id]) => id);
+  const defects = new Set([ids[taskIndex % ids.length]]);
+  const target = tier === "hard" ? 4 + Math.floor(rng() * 2) : 2 + Math.floor(rng() * 2);
+  while (defects.size < target) defects.add(ids[Math.floor(rng() * ids.length)]);
+  return [...defects];
+}
+
+const PROMPT_HEAD = `Fix the broken HTML page below so keyboard, screen-reader, and contrast checks pass.
+
+Repair every defect you find: image text alternatives, input labels, text contrast (4.5:1 or better, or 3:1 for large text), heading order, tab order, native buttons, page language, visible focus styles, link names, and table headers. Keep all visible text and elements; do not delete or hide content to silence a check.
+
+Return the complete fixed HTML document.`;
+
+// Verification imports the real grader from the built package: an
+// expected page is only a valid reference when it scores exactly 1.
+const { benchmark } = await import(new URL("../dist/index.js", import.meta.url).href).catch(() => {
+  throw new Error("dist/index.js not found - run `npm run build` before generating tasks");
+});
+
+// Tokens that mean a template leak: a breaker or builder read a field
+// that does not exist and strung the result into the page.
+const JUNK = /\bundefined\b|\bNaN\b|\[object Object\]|\bnull\b/;
+const assertNoJunk = (where, text) => {
+  if (JUNK.test(text)) throw new Error(`generated ${where} contains a template-leak token`);
+};
+
+// Grade the fixed page as if every check were an injected defect: the
+// score is exactly 1 iff all ten checks pass with real targets. A page
+// that fails any check gets re-drawn; a reference that caps its own
+// task below 1 must never ship.
+const ALL_DEFECTS = CHECKS.map(([id]) => id);
+async function expectedScoresOne(html) {
+  const probe = { id: "a11y-probe", kind: "single", prompt: `\`\`\`html\n${html}\n\`\`\``, expected: html, metadata: { defects: ALL_DEFECTS } };
+  const result = await benchmark.score(probe, { answer: html });
+  return result.score === 1;
+}
+
+const rng = mulberry32(seed);
+const tasks = [];
+const fingerprints = new Set();
+for (let i = 0; i < count; i++) {
+  const tier = i % 3 === 2 ? "hard" : "easy";
+  const build = tier === "hard" ? buildHard : buildFixed;
+  const breakers = tier === "hard" ? HARD_BREAKERS : BREAKERS;
+  let built;
+  for (let attempt = 0; ; attempt += 1) {
+    built = build(rng);
+    assertNoJunk(`page ${i + 1}`, built.html);
+    if (await expectedScoresOne(built.html)) break;
+    if (attempt >= 199) throw new Error(`task ${i + 1}: no clean reference page after 200 draws`);
+  }
+  const defects = pickDefects(rng, i, tier).sort();
+  let broken = built.html;
+  for (const id of defects) {
+    const [breakPage] = breakers[id](built, rng);
+    const next = breakPage(broken);
+    if (next === broken) throw new Error(`breaker ${id} changed nothing on task ${i + 1}`);
+    broken = next;
+  }
+  if (broken === built.html) throw new Error(`task ${i + 1} has no visible break`);
+  assertNoJunk(`task ${i + 1}`, broken);
+  fingerprints.add(createHash("sha1").update(built.html.replace(/>\s*</g, "><").replace(/[\w.-]+(?=\.jpg|"[a-z-]+")/g, "#")).digest("hex").slice(0, 12));
+  const idNum = String(i + 1).padStart(2, "0");
+  tasks.push({
+    id: `${split === "hidden" ? "a11yh" : "a11y"}-${idNum}`,
+    kind: "single",
+    prompt: `${PROMPT_HEAD}\n\n\`\`\`html\n${broken}\n\`\`\``,
+    expected: built.html,
+    metadata: {
+      defects, wcag: defects.map((d) => WCAG[d]), tier, seed, split, taskSeed: seed + i,
+    },
+  });
+  assertNoJunk(`task ${i + 1} prompt`, tasks[tasks.length - 1].prompt);
+}
+const coverage = new Map(CHECKS.map(([id]) => [id, 0]));
+for (const task of tasks) for (const id of task.metadata.defects) coverage.set(id, coverage.get(id) + 1);
+for (const [id, n] of coverage) {
+  if (n < Math.floor(count / CHECKS.length)) throw new Error(`check ${id} appears in only ${n} tasks`);
+}
+// Distinct pages, not six fixed themes: the hidden split cannot reuse a
+// public reference page. Require well above the old six-theme ceiling.
+if (fingerprints.size < Math.min(30, count)) {
+  throw new Error(`only ${fingerprints.size} distinct page fingerprints (need >= ${Math.min(30, count)})`);
+}
+await mkdir(dirname(out), { recursive: true });
+await writeFile(out, `${tasks.map((task) => JSON.stringify(task)).join("\n")}\n`);
+console.log(`generated ${tasks.length} ${split} tasks (seed ${seed}) -> ${out}`);
+console.log(`fingerprints: ${fingerprints.size} distinct pages`);
+console.log(`coverage: ${[...coverage].map(([id, n]) => `${id}=${n}`).join(" ")}`);