Fix css typo

app.py

@@ -9,7 +9,7 @@ CSS ="""
 .gradio-container { height: 100vh !important; }
 .svelte-vt1mxs div:first-child { flex-grow: 1; overflow: auto;}
 #chatbot { flex-grow: 1; overflow: auto;}
-.svelte-vt1mxs > div:nth-child(2) > div:first-child {height: 300px; overflow: auto;}
+.svelte-vt1mxs div:nth-child(2) > div:first-child {height: 300px; overflow: auto;}
 footer {visibility: hidden}
 .app.svelte-182fdeq.svelte-182fdeq {
   max-width: 100vw !important;