Update app.py

app.py

@@ -116,7 +116,7 @@ body {
     max-width: 800px;
     margin: 50px auto;
     padding: 20px;
-    background: linear-gradient(145deg, #827272, #f0f0f0);
+    background: linear-gradient(145deg, #000000, #f0f0f0);
     box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
     border-radius: 10px;
     border: 1px solid #e0e0e0;