body { font-family: Arial, sans-serif; background: #121212; color: #fff; display: flex; justify-content: center; align-items: center; height: 100vh; margin: 0; }
.container { width: 400px; }
#chat-box { height: 300px; overflow-y: auto; border: 1px solid #555; padding: 10px; margin-bottom: 10px; background: #1e1e1e; }
#user-input { width: 75%; padding: 10px; }
#send-btn { padding: 10px; width: 20%; background: #0ff; color: #000; border: none; cursor: pointer; }