diff --git a/app.py b/app.py
index d355d73..327b929 100644
--- a/app.py
+++ b/app.py
@@ -3073,10 +3073,11 @@ def public_frontend():
     .site-logo-sub { font-size:0.62rem; }
     .header-right { display:flex; align-items:center; gap:0.3rem; }
     .header-right a { font-size:0.7rem !important; }
-  }
-    .chat-overlay { bottom:5rem; right:0.5rem; width:calc(100vw - 1rem); max-height:60vh; }
-    .chat-bubble { bottom:1rem; right:1rem; }
-    .submit-overlay { bottom:4rem; right:0.5rem; width:calc(100vw - 1rem); max-height:90vh; }
+    /* Chat & Submit zentriert am unteren Rand */
+    .chat-bubble { bottom:1rem; right:auto; left:50%; transform:translateX(calc(-50% - 32px)); }
+    .submit-bubble { bottom:1rem; right:auto; left:50%; transform:translateX(calc(-50% + 32px)); }
+    .chat-overlay { bottom:5rem; right:0.5rem; left:0.5rem; width:auto; max-height:60vh; }
+    .submit-overlay { bottom:5rem; right:0.5rem; left:0.5rem; width:auto; max-height:85vh; }
   }
   .chat-bubble { position:fixed; bottom:1.5rem; right:1.5rem; z-index:9999;
     width:56px; height:56px; border-radius:50%; background:#1F2937;