diff --git a/.agents/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.agents/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.agents/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.agents/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.claude/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.claude/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.claude/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.claude/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.cursor/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.cursor/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.cursor/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.cursor/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.gemini/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.gemini/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.gemini/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.gemini/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.github/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.github/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.github/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.github/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.grok/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.grok/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.grok/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.grok/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.hermes/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.hermes/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.hermes/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.hermes/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.kiro/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.kiro/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.kiro/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.kiro/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.opencode/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.opencode/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.opencode/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.opencode/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.pi/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.pi/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.pi/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.pi/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.qoder/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.qoder/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.qoder/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.qoder/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.rovodev/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.rovodev/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.rovodev/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.rovodev/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.trae-cn/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.trae-cn/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.trae-cn/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.trae-cn/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.trae/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.trae/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.trae/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.trae/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/.vibe/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/.vibe/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/.vibe/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/.vibe/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }
diff --git a/plugin/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs b/plugin/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
index e5f53b69a..cc36ac9b5 100644
--- a/plugin/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
+++ b/plugin/skills/impeccable/scripts/detector/engines/static-html/css-cascade.mjs
@@ -964,8 +964,34 @@ function buildStaticWindow(staticDoc) {
   };
 }
 
+function resolveLinkedCssPath(fileDir, href) {
+  const stripped = href.split(/[?#]/)[0];
+  const rootRelative = stripped.startsWith('/') && !stripped.startsWith('//');
+  if (!rootRelative) return path.resolve(fileDir, stripped);
+  // Drop "." and reject ".." so /../outside.css cannot walk out of dir.
+  const segments = stripped.replace(/^\/+/, '').split(/[/\\]/).filter(p => p && p !== '.');
+  if (segments.some(p => p === '..')) return path.join(fileDir, segments.filter(p => p !== '..').join(path.sep));
+  const rel = segments.join(path.sep);
+  let dir = fileDir;
+  for (;;) {
+    const parent = path.dirname(dir);
+    if (parent === dir) break; // never use the filesystem root as document root
+    try {
+      const candidate = path.join(dir, rel);
+      if (fs.statSync(candidate).isFile()) return candidate;
+    } catch { /* missing or unreadable candidate */ }
+    // Stop at the project root so a coincidental ~/static/app.css cannot win.
+    try {
+      if (fs.existsSync(path.join(dir, 'package.json')) || fs.existsSync(path.join(dir, '.git'))) break;
+    } catch { /* unreadable marker */ }
+    dir = parent;
+  }
+  return path.join(fileDir, rel);
+}
+
 function collectStaticCssText(root, fileDir, profile, filePath, modules) {
   const styleTexts = [];
+  const warnedMissingStylesheets = new Set();
   for (const styleEl of modules.selectAll('style', root.children || [])) {
     styleTexts.push(modules.domutils.textContent(styleEl));
   }
@@ -974,10 +1000,10 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
     const rel = link.attribs?.rel || '';
     const href = link.attribs?.href || '';
     if (!/\bstylesheet\b/i.test(rel) || !href || /^(https?:)?\/\//i.test(href)) continue;
-    // Cache-busting hrefs (styles.css?v=3) resolve to the file, not to a
-    // literal path with the query in it; a versioned link otherwise made the
-    // whole stylesheet invisible to every element-level check.
-    const cssPath = path.resolve(fileDir, href.split(/[?#]/)[0]);
+    // Cache-busting (styles.css?v=3) and root-relative (/static/app.css) hrefs
+    // must not resolve as OS-absolute paths; otherwise the whole stylesheet is
+    // invisible to every element-level check.
+    const cssPath = resolveLinkedCssPath(fileDir, href);
     try {
       const css = profileStep(profile, {
         engine: 'static-html',
@@ -987,7 +1013,14 @@ function collectStaticCssText(root, fileDir, profile, filePath, modules) {
         detail: href,
       }, () => fs.readFileSync(cssPath, 'utf-8'));
       styleTexts.push(css);
-    } catch { /* skip unreadable */ }
+    } catch {
+      if (!warnedMissingStylesheets.has(cssPath)) {
+        warnedMissingStylesheets.add(cssPath);
+        process.stderr.write(
+          `impeccable detect: could not read linked stylesheet ${href} (resolved to ${cssPath}); color and custom-property rules will be incomplete\n`
+        );
+      }
+    }
   }
   return styleTexts.join('\n');
 }