body { font-family: Arial; margin:0; padding:0; overflow:hidden; }
.container { display:flex; height:100vh; }
.sidebar { width:300px; background:#282c34; color:#fff; overflow-y:auto; padding:10px; }
.profile { padding:10px; cursor:pointer; border-bottom:1px solid #444; }
.profile:hover { background:#444; }
.chat-container { flex:1; display:flex; flex-direction:column; background:#343a46; }
#chat-header { padding:15px; color:#fff; background:#23272f; }
#chat-history { flex:1; padding:10px; overflow-y:auto; color:#fff; }
.chat-input { display:flex; padding:10px; background:#23272f; }
#message-input { flex:1; padding:10px; border:none; }
#send-btn { padding:10px 15px; border:none; cursor:pointer; }
.message { padding:8px; border-radius:5px; margin:5px 0; }
.user { background:#1a4a6d; text-align:right; }
.ai { background:#454a54; }