*{box-sizing:border-box;margin:0;padding:0}body{background:#e0e0e0;min-height:100vh;font-family:-apple-system,Segoe UI,Roboto,sans-serif;font-size:16px}#root{width:100%;max-width:700px;margin:0 auto}.chat-container{border-radius:12px;flex-direction:column;max-width:600px;height:80vh;margin:40px auto;padding:16px;display:flex}.header{justify-content:center;align-items:center;margin-bottom:16px;display:flex;position:relative}.header h2{margin:0;font-size:24px}.header-actions{align-items:center;gap:8px;display:flex;position:absolute;right:0}.theme-toggle{cursor:pointer;background:#fff;border:2px solid #333;border-radius:8px;padding:6px 10px;font-size:20px}.logout-btn{cursor:pointer;background:0 0;border:1px solid #ddd;border-radius:8px;padding:6px 12px;font-size:15px}.messages{background:#f9f9f9;border:1px solid #ddd;border-radius:8px;flex:1;padding:16px;overflow-y:auto}.message{border-radius:8px;max-width:80%;margin-bottom:12px;padding:10px 14px;font-size:18px;line-height:1.5}.message.user{color:#fff;background:#28a745;margin-left:auto}.message.assistant{color:#333;background:#e9e9e9}.input-bar{gap:8px;margin-top:12px;display:flex}.input-bar input{border:1px solid #ddd;border-radius:8px;flex:1;padding:10px;font-size:16px}.input-bar button{color:#fff;cursor:pointer;background:#28a745;border:none;border-radius:8px;padding:10px 20px;font-size:16px}.input-bar button:disabled{background:#ccc}.chat-container.dark{color:#eee;background:#1e1e1e}.chat-container.dark .messages{background:#1a1a1a;border-color:#444}.chat-container.dark .message.assistant{color:#eee;background:#3a3a3a}.chat-container.dark .input-bar input{color:#eee;background:#2a2a2a;border-color:#444}.chat-container.dark .theme-toggle{background:#444;border-color:#eee}.chat-container.dark .logout-btn{color:#eee;border-color:#444}.login-container{text-align:center;margin-top:100px}.login-btn{color:#fff;background:#28a745;border-radius:8px;margin-top:16px;padding:12px 24px;font-size:16px;text-decoration:none;display:inline-block}.copyright{color:#888;margin-top:2rem;font-size:.8rem}