body {
  font-family: sans-serif;
  background: #f5f5f5;
}
.chat-container {
  max-width: 600px;
  margin: 50px auto;
  background: white;
  padding: 20px;
  border-radius: 10px;
}
#chat {
  height: 300px;
  overflow-y: auto;
  margin-bottom: 10px;
}
#user-input {
  width: 80%;
  padding: 10px;
}
button {
  padding: 10px;
}
.message {
  margin: 5px 0;
}
.user { font-weight: bold; color: #0077cc; }
.assistant { color: #333; }