diff --git a/toolgate/scripts/check_file_sizes.py b/toolgate/scripts/check_file_sizes.py
index 8270a58..1237bad 100644
--- a/toolgate/scripts/check_file_sizes.py
+++ b/toolgate/scripts/check_file_sizes.py
@@ -14,13 +14,24 @@
 from pathlib import Path
 
 LIMIT = 600
-SUFFIXES = (".py", ".ts", ".tsx", ".js", ".mjs")
+SUFFIXES = (".py", ".ts", ".tsx", ".js", ".jsx", ".mjs", ".cjs", ".css", ".sh")
 ALLOWLIST = Path("file-size-allowlist.txt")
 
 
 def tracked_sources() -> list[str]:
     out = subprocess.run(["git", "ls-files"], capture_output=True, text=True, check=True).stdout
-    return [path for path in out.splitlines() if path.endswith(SUFFIXES)]
+    return [path for path in out.splitlines() if path.endswith(SUFFIXES) or _script(path)]
+
+
+def _script(path: str) -> bool:
+    """A file with no suffix that starts with "#!" is a script (toolgate/cli/toolgate)."""
+    if "." in Path(path).name:
+        return False
+    try:
+        with open(path, "rb") as handle:
+            return handle.read(2) == b"#!"
+    except OSError:
+        return False
 
 
 def allowlist() -> dict[str, int]:
@@ -39,7 +50,8 @@ def main() -> int:
     allowed = allowlist()
     problems = []
     for path in tracked_sources():
-        lines = Path(path).read_text(encoding="utf-8", errors="replace").count("\n")
+        # splitlines also counts a last line that has no final newline.
+        lines = len(Path(path).read_text(encoding="utf-8", errors="replace").splitlines())
         ceiling = allowed.pop(path, None)
         if ceiling is None and lines > LIMIT:
             problems.append(f"{path}: {lines} lines, limit {LIMIT}. Split it by concern.")
diff --git a/toolgate/tests/test_guard_scripts.py b/toolgate/tests/test_guard_scripts.py
index 1acf898..4b1c5d5 100644
--- a/toolgate/tests/test_guard_scripts.py
+++ b/toolgate/tests/test_guard_scripts.py
@@ -11,6 +11,8 @@
 import sys
 from pathlib import Path
 
+import pytest
+
 SCRIPTS = Path(__file__).resolve().parents[1] / "scripts"
 FILE_SIZES = SCRIPTS / "check_file_sizes.py"
 BOUNDARIES = SCRIPTS / "check_package_boundaries.py"
@@ -62,6 +64,29 @@ def test_file_one_line_over_the_limit_fails(self, tmp_path):
         assert result.returncode == 1
         assert "mod.py: 601 lines, limit 600. Split it by concern." in result.stdout
 
+    @pytest.mark.parametrize("name", ["App.jsx", "theme.css", "run.sh", "tool.cjs"])
+    def test_dashboard_styles_and_shell_files_are_measured(self, tmp_path, name):
+        write(tmp_path, name, source_file(601))
+        track_everything(tmp_path)
+        result = run_script(FILE_SIZES, tmp_path)
+        assert result.returncode == 1
+        assert f"{name}: 601 lines, limit 600." in result.stdout
+
+    def test_a_script_without_a_suffix_is_measured_by_its_shebang(self, tmp_path):
+        write(tmp_path, "bin/toolgate", "#!/usr/bin/env python3\n" + source_file(600))
+        write(tmp_path, "LICENSE", source_file(900))
+        track_everything(tmp_path)
+        result = run_script(FILE_SIZES, tmp_path)
+        assert result.returncode == 1
+        assert result.stdout.strip() == "bin/toolgate: 601 lines, limit 600. Split it by concern."
+
+    def test_a_last_line_without_a_newline_counts(self, tmp_path):
+        write(tmp_path, "mod.py", source_file(600) + "# line 601 without a newline")
+        track_everything(tmp_path)
+        result = run_script(FILE_SIZES, tmp_path)
+        assert result.returncode == 1
+        assert "mod.py: 601 lines, limit 600." in result.stdout
+
     def test_allowlisted_file_at_its_ceiling_passes(self, tmp_path):
         write(tmp_path, "big.py", source_file(700))
         write(tmp_path, FILE_SIZE_ALLOWLIST, "# already large when the check arrived\nbig.py 700\n")