*{box-sizing:border-box;margin:0;padding:0;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif}body{color:#fff;background-color:#1a1a1a}#app{width:100vw;height:100vh;display:flex}#sidebar{background-color:#202123;border-right:1px solid #2d2d2d;flex-direction:column;width:260px;padding:20px;display:flex}#sidebar h2{color:#ececf1;margin-bottom:20px;font-size:1.1rem}#history-list{flex-grow:1;list-style:none;overflow-y:auto}#history-list li{cursor:pointer;white-space:nowrap;text-overflow:ellipsis;color:#c5c5d2;border-radius:5px;margin-bottom:5px;padding:10px;font-size:.9rem;overflow:hidden}#history-list li:hover{background-color:#2a2b32}#chat-area{background-color:#343541;flex-direction:column;flex-grow:1;display:flex;position:relative}#chat-area h1{text-align:center;color:#ececf1;background-color:#202123;border-bottom:1px solid #2d2d2d;padding:20px;font-size:1.5rem}#chat-box{flex-direction:column;flex-grow:1;gap:20px;padding:20px 40px;display:flex;overflow-y:auto}.message{word-wrap:break-word;border-radius:8px;max-width:70%;padding:12px 16px;font-size:.95rem;line-height:1.5}.message.user{color:#fff;background-color:#10a37f;align-self:flex-end}.message.bot{color:#ececf1;background-color:#444654;align-self:flex-start}#input-area{background-color:#343541;gap:15px;padding:20px 40px;display:flex}#user-input{color:#fff;background-color:#40414f;border:1px solid #4d4d4d;border-radius:8px;outline:none;flex-grow:1;padding:14px;font-size:1rem}#user-input:focus{border-color:#10a37f}#send-btn{color:#fff;cursor:pointer;background-color:#10a37f;border:none;border-radius:8px;padding:0 24px;font-weight:600;transition:background-color .2s}#send-btn:hover{background-color:#1a7f64}