ContextualWisdomLab · seonghobae · Sep 13, 2026 · Sep 13, 2026 · Sep 13, 2026 · Sep 13, 2026
diff --git a/.Jules/palette.md b/.Jules/palette.md
@@ -32,3 +32,7 @@
 ## 2026-08-22 - Add aria-labelledby to section landmarks
 **Learning:** `<section>`은 접근성 이름이 있을 때만 `region` 랜드마크로 노출되고, 이름이 없으면 `generic`으로 매핑되어 화면 탐색 랜드마크 목록에 나타나지 않습니다. `id` 속성만으로는 부족합니다.
 **Action:** `<section>`에는 고유한 `id`를 가진 내부 헤딩(`<h2>`)을 `aria-labelledby`로 참조시켜 접근성 이름을 부여합니다. 회귀 테스트가 참조 대상 id의 실재 여부와 아이디가 있는 모든 섹션의 레이블링을 검증합니다.
+
+## 2026-09-13 - 외부 링크 접근성 패턴의 일관성 유지
+**Learning:** index.html에 잘 적용된 외부 링크 안내(aria-describedby="new-window-desc") 패턴이 404.html에는 누락되어 있었다. 보조 페이지(404 등)라도 메인 페이지와 동일한 수준의 접근성을 유지하지 않으면 스크린 리더 사용자에게 혼란을 줄 수 있다.
+**Action:** 앞으로 새로운 페이지를 생성하거나 리뷰할 때, 메인 페이지의 접근성 기준(예: 외부 링크 시각적/보조적 안내)이 모든 HTML 문서에 일관되게 적용되었는지 확인한다.
diff --git a/.github/workflows/static_site_regression.yml b/.github/workflows/static_site_regression.yml
@@ -0,0 +1,67 @@
+name: Static Site Regression
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  static_contracts:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 5
+    steps:
+      - name: Checkout exact source revision
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          persist-credentials: false
+
+      - name: Set up Python
+        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        with:
+          python-version: '3.14'
+
+      - name: Verify exact-head static accessibility contracts
+        shell: bash --noprofile --norc -e -o pipefail {0}
+        run: |
+          test "$(git rev-parse HEAD)" = "${{ github.event.pull_request.head.sha || github.sha }}"
+          python - <<'PY'
+          import inspect
+          from pathlib import Path
+          import runpy
+
+          test_files = (
+              Path("tests/test_404_page.py"),
+              Path("tests/test_external_links.py"),
+          )
+          executed = 0
+          for path in test_files:
+              namespace = runpy.run_path(str(path))
+              checks = sorted(
+                  (name, value)
+                  for name, value in namespace.items()
+                  if name.startswith("test_") and callable(value)
+              )
+              if not checks:
+                  raise AssertionError(f"{path} contains no executable test functions")
+              for name, check in checks:
+                  if inspect.signature(check).parameters:
+                      raise AssertionError(
+                          f"{path}:{name} requires a test fixture; the dependency-free runner cannot execute it"
+                      )
+                  check()
+                  executed += 1
+          if executed == 0:
+              raise AssertionError("no static accessibility contracts executed")
+          print(f"executed {executed} static accessibility contracts")
+          PY
+          python -m compileall -q tests/test_404_page.py tests/test_external_links.py
+          git diff --exit-code
diff --git a/404.html b/404.html
@@ -16,6 +16,7 @@
     <link rel="stylesheet" href="404.css">
   </head>
   <body>
+    <span id="new-window-desc" class="visually-hidden">새 창에서 열림</span>
     <a href="#top" class="skip-link">본문으로 건너뛰기</a>
     <header class="site-header">
       <a class="brand" href="/" aria-label="Contextual Wisdom Lab home">
@@ -31,7 +32,7 @@
         <a href="/#projects">프로젝트</a>
         <a href="/#forks">Fork</a>
         <a href="/#work">작업</a>
-        <a target="_blank" rel="noopener noreferrer" href="https://github.com/ContextualWisdomLab">GitHub</a>
+        <a aria-describedby="new-window-desc" target="_blank" rel="noopener noreferrer" href="https://github.com/ContextualWisdomLab" title="새 창에서 열림">GitHub</a>
       </nav>
     </header>
 
@@ -59,7 +60,7 @@ <h1 class="not-found-title">페이지를 찾을 수 없습니다</h1>
       >
       <p>
         <span>Founded by</span>
-        <a target="_blank" rel="noopener noreferrer" href="https://github.com/seonghobae">Seongho Bae</a>.
+        <a aria-describedby="new-window-desc" target="_blank" rel="noopener noreferrer" href="https://github.com/seonghobae" title="새 창에서 열림">Seongho Bae</a>.
         <span>Context into judgment. Judgment into action.</span>
       </p>
     </footer>

diff --git a/tests/test_404_page.py b/tests/test_404_page.py
@@ -79,3 +79,46 @@ def test_404_assets_referenced_exist_on_disk() -> None:
     """Local image/icon assets referenced by the 404 page must be present."""
     for asset in re.findall(r'(?:href|src)="(assets/[^"#?]+)"', _page()):
         assert (ROOT / asset).is_file(), f"404.html references missing asset {asset}"
+
+
+def test_404_page_external_links_accessible() -> None:
+    """External links on the 404 page must be accessible."""
+    html = _page()
+
+    # Check visually hidden description span
+    assert '<span id="new-window-desc" class="visually-hidden">새 창에서 열림</span>' in html, (
+        "404 page must contain the visually hidden description for new window links"
+    )
+
+    # Verify all external links reference it
+    from html.parser import HTMLParser
+
+    class _LinkParser(HTMLParser):
+        def __init__(self) -> None:
+            super().__init__()
+            self.links: list[dict[str, str | None]] = []
+
+        def handle_starttag(self, tag, attrs) -> None:
+            if tag == "a":
+                self.links.append(dict(attrs))
+
+    parser = _LinkParser()
+    parser.feed(html)
+
+    external_links = [a for a in parser.links if a.get("target") == "_blank"]
+    assert len(external_links) > 0, "404 page should have external links"
+
+    for anchor in external_links:
+        assert anchor.get("aria-describedby") == "new-window-desc", (
+            f"External link {anchor.get('href')} must reference #new-window-desc"
+        )
+        assert anchor.get("title") == "새 창에서 열림", (
+            f"External link {anchor.get('href')} must have the correct title"
+        )
+        rel_tokens = {token.lower() for token in (anchor.get("rel") or "").split()}
+        assert "noopener" in rel_tokens, (
+            f"External link {anchor.get('href')} must keep opener isolation"
+        )
+        assert "noreferrer" in rel_tokens, (
+            f"External link {anchor.get('href')} must keep the product referrer policy"
+        )
diff --git a/tests/test_external_links.py b/tests/test_external_links.py
@@ -32,43 +32,56 @@ def handle_starttag(self, tag, attrs) -> None:
             self.links.append(attributes)
 
 
-def _parse_index() -> _LinkParser:
+def _parse_html(file_path: Path) -> _LinkParser:
     parser = _LinkParser()
-    parser.feed(INDEX.read_text(encoding="utf-8"))
-    assert parser.links, "homepage must contain at least one anchor"
+    parser.feed(file_path.read_text(encoding="utf-8"))
     return parser
 
 
-def _external_links(parser: _LinkParser) -> list[dict[str, str | None]]:
+def _external_links(parser: _LinkParser, file_name: str) -> list[dict[str, str | None]]:
     external = [a for a in parser.links if a.get("target") == "_blank"]
-    assert external, "homepage must contain at least one external link"
     return external
 
 
 def test_external_links_reference_the_new_window_description() -> None:
     """Every external link points at the shared visually hidden warning."""
-    parser = _parse_index()
-
-    assert DESC_ID in parser.ids, (
-        f"homepage must define the #{DESC_ID} description element"
-    )
-    for anchor in _external_links(parser):
-        assert anchor.get("aria-describedby") == DESC_ID, (
-            f"External link {anchor.get('href')} must reference #{DESC_ID}"
+    for html_file in ROOT.rglob("*.html"):
+        if ".git" in html_file.parts or ".pytest_cache" in html_file.parts or "components" in html_file.parts:
+            continue
+
+        parser = _parse_html(html_file)
+        external = _external_links(parser, html_file.name)
+        if not external:
+            continue
+
+        assert DESC_ID in parser.ids, (
+            f"{html_file.name} must define the #{DESC_ID} description element"
         )
+        for anchor in external:
+            assert anchor.get("aria-describedby") == DESC_ID, (
+                f"External link {anchor.get('href')} in {html_file.name} must reference #{DESC_ID}"
+            )
 
 
 def test_external_links_keep_the_localized_title() -> None:
     """The title stays as supplemental hover metadata in both locales."""
-    parser = _parse_index()
+    for html_file in ROOT.rglob("*.html"):
+        if ".git" in html_file.parts or ".pytest_cache" in html_file.parts or "components" in html_file.parts:
+            continue
 
-    for anchor in _external_links(parser):
-        assert anchor.get("title") == EXPECTED["title"], (
-            f"External link {anchor.get('href')} is missing the Korean title"
-        )
-        assert anchor.get("data-i18n-title") == EXPECTED["key"], (
-            f"External link {anchor.get('href')} is missing data-i18n-title"
-        )
+        parser = _parse_html(html_file)
+        external = _external_links(parser, html_file.name)
+
+        for anchor in external:
+            assert anchor.get("title") == EXPECTED["title"], (
+                f"External link {anchor.get('href')} in {html_file.name} is missing the Korean title"
+            )
+
+            # 404.html does not load i18n.js, so we only expect data-i18n-title on the homepage
+            if html_file.name == "index.html":
+                assert anchor.get("data-i18n-title") == EXPECTED["key"], (
+                    f"External link {anchor.get('href')} is missing data-i18n-title"
+                )
 
 
 def test_i18n_has_new_tab_translation() -> None:
@@ -82,19 +95,35 @@ def test_visually_hidden_class_is_defined() -> None:
     """The description element relies on a CSP-safe external class."""
     css = (ROOT / "styles.css").read_text(encoding="utf-8")
     assert ".visually-hidden {" in css
-    index = INDEX.read_text(encoding="utf-8")
-    assert f'id="{DESC_ID}" class="visually-hidden"' in index
+    for html_file in ROOT.rglob("*.html"):
+        if ".git" in html_file.parts or ".pytest_cache" in html_file.parts or "components" in html_file.parts:
+            continue
+
+        parser = _parse_html(html_file)
+        external = _external_links(parser, html_file.name)
+        if not external:
+            continue
+
+        html_content = html_file.read_text(encoding="utf-8")
+        assert f'id="{DESC_ID}" class="visually-hidden"' in html_content, (
+            f"{html_file.name} must define the visually-hidden class on the description element"
+        )
 
 
 def test_external_links_keep_opener_and_referrer_policy() -> None:
     """Every new-context link retains explicit opener isolation and referrer policy."""
-    parser = _parse_index()
-
-    for anchor in _external_links(parser):
-        rel_tokens = {token.lower() for token in (anchor.get("rel") or "").split()}
-        assert "noopener" in rel_tokens, (
-            f"External link {anchor.get('href')} must keep opener isolation"
-        )
-        assert "noreferrer" in rel_tokens, (
-            f"External link {anchor.get('href')} must keep the product referrer policy"
-        )
+    for html_file in ROOT.rglob("*.html"):
+        if ".git" in html_file.parts or ".pytest_cache" in html_file.parts or "components" in html_file.parts:
+            continue
+
+        parser = _parse_html(html_file)
+        external = _external_links(parser, html_file.name)
+
+        for anchor in external:
+            rel_tokens = {token.lower() for token in (anchor.get("rel") or "").split()}
+            assert "noopener" in rel_tokens, (
+                f"External link {anchor.get('href')} in {html_file.name} must keep opener isolation"
+            )
+            assert "noreferrer" in rel_tokens, (
+                f"External link {anchor.get('href')} in {html_file.name} must keep the product referrer policy"
+            )