feat: add image to the background

app.py

@@ -30,7 +30,7 @@ body {
     margin: 0 auto;
     max-width: 960px;
     background-color: rgba(255, 255, 255, 0.85);
-    border-radius: 16px;
+    border-radius: 20px;
     box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
     padding: 24px;
     backdrop-filter: blur(10px);