*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:#0f0f0f;color:#e0e0e0;height:100vh;overflow:hidden}#root{height:100vh}.loading{display:flex;align-items:center;justify-content:center;height:100vh;color:#888;font-size:16px}.login-overlay{display:flex;align-items:center;justify-content:center;height:100vh;background:#0f0f0f}.login-modal{background:#1a1a1a;border:1px solid #2a2a2a;border-radius:16px;padding:40px 32px;width:100%;max-width:380px;margin:16px}.login-modal h2{font-size:24px;font-weight:700;color:#fff;text-align:center;margin-bottom:4px}.login-subtitle{text-align:center;color:#888;font-size:14px;margin-bottom:28px}.login-modal form{display:flex;flex-direction:column;gap:12px}.login-modal input{padding:12px 16px;border-radius:10px;border:1px solid #3a3a3a;background:#2a2a2a;color:#e0e0e0;font-size:14px;font-family:inherit;outline:none}.login-modal input:focus{border-color:#2563eb}.login-error{color:#ef4444;font-size:13px;text-align:center}.login-modal button{padding:12px;border-radius:10px;border:none;background:#2563eb;color:#fff;font-size:15px;font-weight:500;cursor:pointer;transition:background .15s;margin-top:4px}.login-modal button:hover:not(:disabled){background:#1d4ed8}.login-modal button:disabled{background:#3a3a3a;color:#888;cursor:not-allowed}.chat-app{display:flex;flex-direction:column;height:100vh;max-width:800px;margin:0 auto}header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid #2a2a2a;background:#1a1a1a}header h1{font-size:18px;font-weight:600;color:#fff}.header-right{display:flex;align-items:center;gap:10px}.header-right select{padding:6px 12px;border-radius:8px;border:1px solid #3a3a3a;background:#2a2a2a;color:#e0e0e0;font-size:13px;cursor:pointer}.logout-btn{padding:6px 14px;border-radius:8px;border:1px solid #3a3a3a;background:transparent;color:#e0e0e0;font-size:13px;cursor:pointer;transition:background .15s,border-color .15s}.logout-btn:hover{background:#2a2a2a;border-color:#ef4444;color:#ef4444}.messages{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:16px}.empty-state{color:#555;text-align:center;margin-top:40%;font-size:15px}.message{padding:12px 16px;border-radius:12px;max-width:85%;line-height:1.5;font-size:14px;white-space:pre-wrap;word-wrap:break-word}.message.user{background:#2563eb;color:#fff;align-self:flex-end;border-bottom-right-radius:4px}.message.assistant{background:#1e1e1e;border:1px solid #2a2a2a;align-self:flex-start;border-bottom-left-radius:4px}.message.assistant .cursor{display:inline-block;width:7px;height:16px;background:#60a5fa;vertical-align:text-bottom;animation:blink .8s infinite}@keyframes blink{0%,to{opacity:1}50%{opacity:0}}.input-area{display:flex;gap:10px;padding:16px 20px;border-top:1px solid #2a2a2a;background:#1a1a1a}.input-area textarea{flex:1;padding:12px 16px;border-radius:12px;border:1px solid #3a3a3a;background:#2a2a2a;color:#e0e0e0;font-size:14px;font-family:inherit;resize:none;outline:none;max-height:120px}.input-area textarea:focus{border-color:#2563eb}.input-area button{padding:12px 24px;border-radius:12px;border:none;background:#2563eb;color:#fff;font-size:14px;font-weight:500;cursor:pointer;transition:background .15s}.input-area button:hover:not(:disabled){background:#1d4ed8}.input-area button:disabled{background:#3a3a3a;color:#888;cursor:not-allowed}.messages::-webkit-scrollbar{width:6px}.messages::-webkit-scrollbar-track{background:transparent}.messages::-webkit-scrollbar-thumb{background:#3a3a3a;border-radius:3px}@media (max-width: 600px){header{padding:12px 14px}header h1{font-size:16px}.header-right select{font-size:12px;padding:5px 8px}.logout-btn{font-size:12px;padding:5px 10px}.messages{padding:12px;gap:12px}.message{padding:10px 14px;font-size:13px;max-width:90%}.input-area{padding:12px;gap:8px}.input-area textarea{padding:10px 14px;font-size:16px}.input-area button{padding:10px 16px;font-size:14px}}