Update app.py

app.py

@@ -15,13 +15,13 @@ def _key_and_nonce():
     img_bytes = (ASSET_IMG.read_bytes() if ASSET_IMG.exists() else b"")
     key = hashlib.sha256(img_bytes).digest()  # 32 bytes (AES-256)
 
-    # Nonce (8 bytes)
+    # Nonce (8 bytes) derived from first line of requirements.txt
     rl = ""
     if REQUIREMENTS.exists():
         with REQUIREMENTS.open("r", encoding="utf-8", errors="ignore") as f:
             rl = (f.readline() or "").strip()
     nonce_src = hashlib.sha1(rl.encode("utf-8")).digest()
-    nonce = nonce_src[:8] if nonce_src else b"\x00"*8
+    nonce = nonce_src[:8] if nonce_src else b"\x00" * 8
 
     return key, nonce
 
@@ -50,18 +50,36 @@ def verify(candidate: str):
         return ("✅ Correct.", flag)
     return ("❌ Incorrect.", "")
 
-with gr.Blocks(title="ENUSEC Freshers – Decrypter 2025") as demo:
-    gr.Markdown(
-        """
+custom_css = """
+#hero { display: flex; gap: 16px; align-items: center; }
+#hero .title h1 { margin: 0; }
+"""
+
+with gr.Blocks(title="ENUSEC Freshers – Decrypter 2025", css=custom_css) as demo:
+    # Hero row with mascot + title
+    with gr.Row(elem_id="hero"):
+        gr.Image(
+            value=str(ASSET_IMG) if ASSET_IMG.exists() else None,
+            show_label=False,
+            interactive=False,
+            height=160,
+            visible=ASSET_IMG.exists()
+        )
+        gr.Markdown(
+            """
 # Decrypter 2025
-Click **Get Encrypted Blob** to receive a Base64 string.
+Click **Get Encrypted Blob** to receive a Base64 string.  
 Submit the flag when you have it.
-        """
-    )
+            """,
+            elem_classes=["title"]
+        )
+
+    # Ciphertext section
     b = gr.Button("Get Encrypted Blob")
     blob = gr.Textbox(label="Ciphertext (Base64)", interactive=False)
     b.click(get_ciphertext, None, blob)
 
+    # Submission section
     gr.Markdown("## Submit Flag")
     guess = gr.Textbox(label="freshers{...}")
     submit = gr.Button("Submit")