diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 6189bc8..aa1762e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -13,14 +13,19 @@ Thanks for your interest in contributing.
 
 ## Local Validation
 
-The CI runs three mandatory checks. Run **all of them locally** before pushing:
+The CI runs four mandatory checks. Run **all of them locally** before pushing or opening a PR:
 
 ```bash
-cargo fmt --check     # style: must pass without diff
-cargo clippy -- -D warnings  # lints: zero warnings allowed
-cargo test            # tests: all must pass
+./ci-check.sh
 ```
 
+This executes:
+
+- `cargo fmt --all -- --check` — style: must pass without diff
+- `cargo clippy --all-targets --all-features -- -D warnings` — lints: zero warnings allowed
+- `cargo test --all-targets --all-features` — tests: all must pass
+- `cargo audit` — dependency vulnerability scan
+
 To auto-fix formatting issues:
 
 ```bash
diff --git a/ci-check.sh b/ci-check.sh
index a78891e..1fc12af 100755
--- a/ci-check.sh
+++ b/ci-check.sh
@@ -1,16 +1,20 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-echo "=== cargo fmt --check ==="
-cargo fmt --check
+echo "=== cargo fmt --all -- --check ==="
+cargo fmt --all -- --check
 
 echo ""
-echo "=== cargo clippy -- -D warnings ==="
-cargo clippy -- -D warnings
+echo "=== cargo clippy --all-targets --all-features -- -D warnings ==="
+cargo clippy --all-targets --all-features -- -D warnings
 
 echo ""
-echo "=== cargo test ==="
-cargo test
+echo "=== cargo test --all-targets --all-features ==="
+cargo test --all-targets --all-features
+
+echo ""
+echo "=== cargo audit ==="
+cargo audit --ignore RUSTSEC-2023-0071
 
 echo ""
 echo "All CI checks passed."
diff --git a/src/app/theme.rs b/src/app/theme.rs
index 1f3a032..b7bb2cd 100644
--- a/src/app/theme.rs
+++ b/src/app/theme.rs
@@ -224,7 +224,7 @@ mod tests {
         let embedded = EMBEDDED_THEMES.iter().find(|(n, _)| *n == "Berlin");
         assert!(embedded.is_some(), "Berlin not in EMBEDDED_THEMES");
         if let Some((_, content)) = embedded {
-            assert!(content.len() > 0, "Berlin embed content is empty");
+            assert!(!content.is_empty(), "Berlin embed content is empty");
             eprintln!("Berlin embed content: {content}");
         }
         // Verify load_theme_by_name returns Berlin