diff --git a/.claude/skills/design-system/scripts/embed-tokens.cjs b/.claude/skills/design-system/scripts/embed-tokens.cjs
index 419c104..e677f0c 100644
--- a/.claude/skills/design-system/scripts/embed-tokens.cjs
+++ b/.claude/skills/design-system/scripts/embed-tokens.cjs
@@ -15,12 +15,16 @@ const path = require('path');
 
 // Find project root (look for assets/design-tokens.css)
 function findProjectRoot(startDir) {
+  // Walk up until dirname stops changing: on Windows the root is 'C:\', so a
+  // `dir !== '/'` guard never terminates.
   let dir = startDir;
-  while (dir !== '/') {
+  for (;;) {
     if (fs.existsSync(path.join(dir, 'assets', 'design-tokens.css'))) {
       return dir;
     }
-    dir = path.dirname(dir);
+    const parent = path.dirname(dir);
+    if (parent === dir) break;
+    dir = parent;
   }
   return null;
 }
diff --git a/.claude/skills/design-system/scripts/fetch-background.py b/.claude/skills/design-system/scripts/fetch-background.py
index bcbd357..08a9970 100644
--- a/.claude/skills/design-system/scripts/fetch-background.py
+++ b/.claude/skills/design-system/scripts/fetch-background.py
@@ -9,10 +9,32 @@ import json
 import csv
 import re
 import sys
+import os
 from pathlib import Path
 
-# Project root relative to this script
-PROJECT_ROOT = Path(__file__).parent.parent.parent.parent.parent
+# The skill can be installed outside the project it operates on (user-level
+# ~/.claude/skills/, or as a plugin), so the project root cannot be derived from
+# this file's location. Resolve it from the working directory instead -- the same
+# convention generate-tokens.cjs and validate-tokens.cjs already use via
+# process.cwd(). DESIGN_SYSTEM_PROJECT_ROOT overrides it explicitly.
+def _find_project_root():
+    override = os.environ.get('DESIGN_SYSTEM_PROJECT_ROOT')
+    if override:
+        return Path(override).resolve()
+    start = Path.cwd().resolve()
+    markers = (
+        Path('assets') / 'design-tokens.json',
+        Path('assets') / 'design-tokens.css',
+        Path('package.json'),
+        Path('.git'),
+    )
+    for candidate in (start, *start.parents):
+        if any((candidate / marker).exists() for marker in markers):
+            return candidate
+    return start
+
+
+PROJECT_ROOT = _find_project_root()
 TOKENS_PATH = PROJECT_ROOT / 'assets' / 'design-tokens.json'
 BACKGROUNDS_CSV = Path(__file__).parent.parent / 'data' / 'slide-backgrounds.csv'
 
diff --git a/.claude/skills/design-system/scripts/html-token-validator.py b/.claude/skills/design-system/scripts/html-token-validator.py
index a722498..2b9c5d0 100644
--- a/.claude/skills/design-system/scripts/html-token-validator.py
+++ b/.claude/skills/design-system/scripts/html-token-validator.py
@@ -15,11 +15,43 @@ Usage:
 import re
 import json
 import sys
+import os
 from pathlib import Path
 from typing import Dict, List, Tuple, Optional
 
-# Project root relative to this script
-PROJECT_ROOT = Path(__file__).parent.parent.parent.parent.parent
+# The skill can be installed outside the project it operates on (user-level
+# ~/.claude/skills/, or as a plugin), so the project root cannot be derived from
+# this file's location. Resolve it from the working directory instead -- the same
+# convention generate-tokens.cjs and validate-tokens.cjs already use via
+# process.cwd(). DESIGN_SYSTEM_PROJECT_ROOT overrides it explicitly.
+def _find_project_root():
+    override = os.environ.get('DESIGN_SYSTEM_PROJECT_ROOT')
+    if override:
+        return Path(override).resolve()
+    start = Path.cwd().resolve()
+    markers = (
+        Path('assets') / 'design-tokens.json',
+        Path('assets') / 'design-tokens.css',
+        Path('package.json'),
+        Path('.git'),
+    )
+    for candidate in (start, *start.parents):
+        if any((candidate / marker).exists() for marker in markers):
+            return candidate
+    return start
+
+
+PROJECT_ROOT = _find_project_root()
+
+# Force UTF-8 on stdout/stderr: this script prints emoji, which raises
+# UnicodeEncodeError on a Windows console (cp1252). Same guard as
+# src/ui-ux-pro-max/scripts/search.py.
+import io
+
+if sys.stdout.encoding and sys.stdout.encoding.lower() != 'utf-8':
+    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8')
+if sys.stderr.encoding and sys.stderr.encoding.lower() != 'utf-8':
+    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding='utf-8')
 TOKENS_JSON_PATH = PROJECT_ROOT / 'assets' / 'design-tokens.json'
 TOKENS_CSS_PATH = PROJECT_ROOT / 'assets' / 'design-tokens.css'
 
diff --git a/.claude/skills/design-system/scripts/search-slides.py b/.claude/skills/design-system/scripts/search-slides.py
index ff5200a..fc9ce74 100755
--- a/.claude/skills/design-system/scripts/search-slides.py
+++ b/.claude/skills/design-system/scripts/search-slides.py
@@ -13,6 +13,16 @@ from slide_search_core import (
     get_color_for_emotion, get_background_config
 )
 
+# Force UTF-8 on stdout/stderr: this script prints emoji, which raises
+# UnicodeEncodeError on a Windows console (cp1252). Same guard as
+# src/ui-ux-pro-max/scripts/search.py.
+import io
+
+if sys.stdout.encoding and sys.stdout.encoding.lower() != 'utf-8':
+    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8')
+if sys.stderr.encoding and sys.stderr.encoding.lower() != 'utf-8':
+    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding='utf-8')
+
 
 def format_result(result, domain):
     """Format a single search result for display"""
diff --git a/.claude/skills/design-system/scripts/tests/test_validate_tokens.py b/.claude/skills/design-system/scripts/tests/test_validate_tokens.py
index bbde4ec..6754246 100644
--- a/.claude/skills/design-system/scripts/tests/test_validate_tokens.py
+++ b/.claude/skills/design-system/scripts/tests/test_validate_tokens.py
@@ -20,11 +20,15 @@ def _run(tmp_path: Path, css: str) -> subprocess.CompletedProcess:
     node = shutil.which("node")
     if not node:
         pytest.skip("node not available")
-    (tmp_path / "sample.css").write_text(css)
+    (tmp_path / "sample.css").write_text(css, encoding="utf-8")
     return subprocess.run(
         [node, str(SCRIPT), "--dir", str(tmp_path)],
         capture_output=True,
         text=True,
+        # validate-tokens.cjs prints emoji; without an explicit encoding Python
+        # decodes the pipe with the locale codec (cp1252 on Windows), which
+        # raises in the reader thread and leaves result.stdout set to None.
+        encoding="utf-8",
     )
 
 
diff --git a/cli/assets/skills/design-system/scripts/embed-tokens.cjs b/cli/assets/skills/design-system/scripts/embed-tokens.cjs
index 419c104..e677f0c 100644
--- a/cli/assets/skills/design-system/scripts/embed-tokens.cjs
+++ b/cli/assets/skills/design-system/scripts/embed-tokens.cjs
@@ -15,12 +15,16 @@ const path = require('path');
 
 // Find project root (look for assets/design-tokens.css)
 function findProjectRoot(startDir) {
+  // Walk up until dirname stops changing: on Windows the root is 'C:\', so a
+  // `dir !== '/'` guard never terminates.
   let dir = startDir;
-  while (dir !== '/') {
+  for (;;) {
     if (fs.existsSync(path.join(dir, 'assets', 'design-tokens.css'))) {
       return dir;
     }
-    dir = path.dirname(dir);
+    const parent = path.dirname(dir);
+    if (parent === dir) break;
+    dir = parent;
   }
   return null;
 }
diff --git a/cli/assets/skills/design-system/scripts/fetch-background.py b/cli/assets/skills/design-system/scripts/fetch-background.py
index bcbd357..08a9970 100644
--- a/cli/assets/skills/design-system/scripts/fetch-background.py
+++ b/cli/assets/skills/design-system/scripts/fetch-background.py
@@ -9,10 +9,32 @@ import json
 import csv
 import re
 import sys
+import os
 from pathlib import Path
 
-# Project root relative to this script
-PROJECT_ROOT = Path(__file__).parent.parent.parent.parent.parent
+# The skill can be installed outside the project it operates on (user-level
+# ~/.claude/skills/, or as a plugin), so the project root cannot be derived from
+# this file's location. Resolve it from the working directory instead -- the same
+# convention generate-tokens.cjs and validate-tokens.cjs already use via
+# process.cwd(). DESIGN_SYSTEM_PROJECT_ROOT overrides it explicitly.
+def _find_project_root():
+    override = os.environ.get('DESIGN_SYSTEM_PROJECT_ROOT')
+    if override:
+        return Path(override).resolve()
+    start = Path.cwd().resolve()
+    markers = (
+        Path('assets') / 'design-tokens.json',
+        Path('assets') / 'design-tokens.css',
+        Path('package.json'),
+        Path('.git'),
+    )
+    for candidate in (start, *start.parents):
+        if any((candidate / marker).exists() for marker in markers):
+            return candidate
+    return start
+
+
+PROJECT_ROOT = _find_project_root()
 TOKENS_PATH = PROJECT_ROOT / 'assets' / 'design-tokens.json'
 BACKGROUNDS_CSV = Path(__file__).parent.parent / 'data' / 'slide-backgrounds.csv'
 
diff --git a/cli/assets/skills/design-system/scripts/html-token-validator.py b/cli/assets/skills/design-system/scripts/html-token-validator.py
index a722498..2b9c5d0 100644
--- a/cli/assets/skills/design-system/scripts/html-token-validator.py
+++ b/cli/assets/skills/design-system/scripts/html-token-validator.py
@@ -15,11 +15,43 @@ Usage:
 import re
 import json
 import sys
+import os
 from pathlib import Path
 from typing import Dict, List, Tuple, Optional
 
-# Project root relative to this script
-PROJECT_ROOT = Path(__file__).parent.parent.parent.parent.parent
+# The skill can be installed outside the project it operates on (user-level
+# ~/.claude/skills/, or as a plugin), so the project root cannot be derived from
+# this file's location. Resolve it from the working directory instead -- the same
+# convention generate-tokens.cjs and validate-tokens.cjs already use via
+# process.cwd(). DESIGN_SYSTEM_PROJECT_ROOT overrides it explicitly.
+def _find_project_root():
+    override = os.environ.get('DESIGN_SYSTEM_PROJECT_ROOT')
+    if override:
+        return Path(override).resolve()
+    start = Path.cwd().resolve()
+    markers = (
+        Path('assets') / 'design-tokens.json',
+        Path('assets') / 'design-tokens.css',
+        Path('package.json'),
+        Path('.git'),
+    )
+    for candidate in (start, *start.parents):
+        if any((candidate / marker).exists() for marker in markers):
+            return candidate
+    return start
+
+
+PROJECT_ROOT = _find_project_root()
+
+# Force UTF-8 on stdout/stderr: this script prints emoji, which raises
+# UnicodeEncodeError on a Windows console (cp1252). Same guard as
+# src/ui-ux-pro-max/scripts/search.py.
+import io
+
+if sys.stdout.encoding and sys.stdout.encoding.lower() != 'utf-8':
+    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8')
+if sys.stderr.encoding and sys.stderr.encoding.lower() != 'utf-8':
+    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding='utf-8')
 TOKENS_JSON_PATH = PROJECT_ROOT / 'assets' / 'design-tokens.json'
 TOKENS_CSS_PATH = PROJECT_ROOT / 'assets' / 'design-tokens.css'
 
diff --git a/cli/assets/skills/design-system/scripts/search-slides.py b/cli/assets/skills/design-system/scripts/search-slides.py
index ff5200a..fc9ce74 100644
--- a/cli/assets/skills/design-system/scripts/search-slides.py
+++ b/cli/assets/skills/design-system/scripts/search-slides.py
@@ -13,6 +13,16 @@ from slide_search_core import (
     get_color_for_emotion, get_background_config
 )
 
+# Force UTF-8 on stdout/stderr: this script prints emoji, which raises
+# UnicodeEncodeError on a Windows console (cp1252). Same guard as
+# src/ui-ux-pro-max/scripts/search.py.
+import io
+
+if sys.stdout.encoding and sys.stdout.encoding.lower() != 'utf-8':
+    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8')
+if sys.stderr.encoding and sys.stderr.encoding.lower() != 'utf-8':
+    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding='utf-8')
+
 
 def format_result(result, domain):
     """Format a single search result for display"""
diff --git a/cli/assets/skills/design-system/scripts/tests/test_validate_tokens.py b/cli/assets/skills/design-system/scripts/tests/test_validate_tokens.py
index bbde4ec..6754246 100644
--- a/cli/assets/skills/design-system/scripts/tests/test_validate_tokens.py
+++ b/cli/assets/skills/design-system/scripts/tests/test_validate_tokens.py
@@ -20,11 +20,15 @@ def _run(tmp_path: Path, css: str) -> subprocess.CompletedProcess:
     node = shutil.which("node")
     if not node:
         pytest.skip("node not available")
-    (tmp_path / "sample.css").write_text(css)
+    (tmp_path / "sample.css").write_text(css, encoding="utf-8")
     return subprocess.run(
         [node, str(SCRIPT), "--dir", str(tmp_path)],
         capture_output=True,
         text=True,
+        # validate-tokens.cjs prints emoji; without an explicit encoding Python
+        # decodes the pipe with the locale codec (cp1252 on Windows), which
+        # raises in the reader thread and leaves result.stdout set to None.
+        encoding="utf-8",
     )