.container{max-width:600px;margin:40px auto;padding:20px;font-family:sans-serif;border:1px solid #ccc;border-radius:8px;background:#fdfdfd}.description{margin-bottom:20px;font-style:italic;color:#555}.chat-window{height:300px;overflow-y:auto;border:1px solid #ddd;padding:10px;margin-bottom:10px;background:#fff}.message{margin-bottom:10px;padding:8px;border-radius:5px}.message.user{background:#d0f0ff;text-align:right}.message.agent{background:#f0f0f0}.input-area{display:flex;gap:10px}input[type=text]{flex:1;padding:10px;font-size:1em}