html,body,#root{height:100%;margin:0;padding:0;background:#f5f5f5}.app-container{display:flex;flex-direction:column;width:1200px;height:100%;margin:0 auto}.chat-body{flex:1;overflow-y:auto;padding:16px;background:#fff}.chat-input{border-top:1px solid #ddd;padding:12px 16px;background:#fff}