diff --git a/Mathematics/Fundamentals/HackerRank/Claude/Easy/Restaurant/Restaurant.md b/Mathematics/Fundamentals/HackerRank/Claude/Easy/Restaurant/Restaurant.md
index a6199d0f..82da7bbc 100644
--- a/Mathematics/Fundamentals/HackerRank/Claude/Easy/Restaurant/Restaurant.md
+++ b/Mathematics/Fundamentals/HackerRank/Claude/Easy/Restaurant/Restaurant.md
@@ -210,10 +210,7 @@ from __future__ import annotations
 
 import math
 import os
-from typing import TYPE_CHECKING
 
-if TYPE_CHECKING:
-    pass
 
 
 def restaurant(l: int, b: int) -> int:
@@ -298,12 +295,12 @@ if __name__ == '__main__':
 ### 定数倍削減テクニック
 
 ```python
-# ❌ 非効率: 中間変数の無駄な生成
+# 可読性重視: 中間変数を使った例
 area = l * b
 square_area = g * g
 result = area // square_area
 
-# ✅ 最適: 1行で計算
+# より簡潔に書ける
 result = (l * b) // (g * g)
 ```
 
diff --git a/calc_sri_fix.sh b/calc_sri_fix.sh
old mode 100644
new mode 100755
index f3974247..e71fa62f
--- a/calc_sri_fix.sh
+++ b/calc_sri_fix.sh
@@ -1,9 +1,28 @@
 #!/bin/bash
 
+set -euo pipefail
+
 calculate_sri() {
     url="$1"
-    hash=$(curl -sL "$url" | openssl dgst -sha384 -binary | openssl base64 -A)
+    temp_file=$(mktemp)
+
+    # curl options: -f (fail on HTTP error), -S (show error), -s (silent equivalent), -L (follow redirects)
+    if ! curl -fS -sL "$url" -o "$temp_file"; then
+        echo "Error downloading $url" >&2
+        rm -f "$temp_file"
+        return 1
+    fi
+
+    # Check for empty response
+    if [ ! -s "$temp_file" ]; then
+        echo "Error: Empty response from $url" >&2
+        rm -f "$temp_file"
+        return 1
+    fi
+
+    hash=$(openssl dgst -sha384 -binary < "$temp_file" | openssl base64 -A)
     echo "$url sha384-$hash"
+    rm -f "$temp_file"
 }
 
 calculate_sri "https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/plugins/line-numbers/prism-line-numbers.min.js"