:root{--bg: #0d1117;--bg-elev: #151b24;--bg-sidebar: #0a0e14;--border: #232b36;--text: #e6edf3;--text-dim: #8b97a7;--accent: #2dd4bf;--accent-deep: #0e7490;--user-bubble: #1c2530;--danger: #f47174;--radius: 12px;--font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%}body{font-family:var(--font);background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;line-height:1.6}button{font-family:inherit;cursor:pointer}input,textarea{font-family:inherit;background:var(--bg-elev);border:1px solid var(--border);color:var(--text);border-radius:var(--radius);padding:12px 14px;font-size:15px;outline:none;transition:border-color .15s}input:focus,textarea:focus{border-color:var(--accent)}::-webkit-scrollbar{width:8px}::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}.app{display:flex;height:100vh}.sidebar{width:280px;background:var(--bg-sidebar);border-right:1px solid var(--border);display:flex;flex-direction:column;flex-shrink:0}.brand{padding:20px 18px;font-size:22px;font-weight:700;letter-spacing:-.5px;display:flex;align-items:center;gap:10px}.brand .dot{width:10px;height:10px;border-radius:50%;background:var(--accent);box-shadow:0 0 12px var(--accent)}.new-chat{margin:0 14px 12px;padding:11px;background:transparent;border:1px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:14px;font-weight:500;display:flex;align-items:center;justify-content:center;gap:8px;transition:background .15s,border-color .15s}.new-chat:hover{background:var(--bg-elev);border-color:var(--accent-deep)}.conv-list{flex:1;overflow-y:auto;padding:0 8px}.conv-item{padding:10px 12px;border-radius:8px;font-size:14px;color:var(--text-dim);cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:8px;white-space:nowrap;overflow:hidden}.conv-item:hover,.conv-item.active{background:var(--bg-elev);color:var(--text)}.conv-item span{overflow:hidden;text-overflow:ellipsis}.conv-item .del{opacity:0;border:none;background:none;color:var(--text-dim);font-size:16px;flex-shrink:0;transition:opacity .15s,color .15s}.conv-item:hover .del{opacity:1}.conv-item .del:hover{color:var(--danger)}.sidebar-foot{padding:14px 18px;border-top:1px solid var(--border);font-size:13px;color:var(--text-dim);display:flex;align-items:center;justify-content:space-between}.sidebar-foot button{background:none;border:none;color:var(--text-dim);font-size:13px}.sidebar-foot button:hover{color:var(--accent)}.chat{flex:1;display:flex;flex-direction:column;min-width:0}.messages{flex:1;overflow-y:auto;display:flex;flex-direction:column;align-items:center}.messages-inner{width:100%;max-width:760px;padding:32px 20px 120px}.msg{display:flex;gap:16px;margin-bottom:28px}.msg .avatar{width:30px;height:30px;border-radius:7px;flex-shrink:0;display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:700}.msg.user .avatar{background:var(--user-bubble);color:var(--text-dim)}.msg.assistant .avatar{background:var(--accent-deep);color:#fff}.msg .body{padding-top:4px;white-space:pre-wrap;word-wrap:break-word;flex:1}.msg .role{font-size:13px;font-weight:600;color:var(--text-dim);margin-bottom:2px}.cursor:after{content:"▋";color:var(--accent);animation:blink 1s steps(2) infinite}@keyframes blink{0%,50%{opacity:1}51%,to{opacity:0}}.composer-wrap{position:sticky;bottom:0;display:flex;justify-content:center;background:linear-gradient(transparent,var(--bg) 30%);padding:0 20px 24px}.composer{width:100%;max-width:760px;display:flex;gap:10px;align-items:flex-end;background:var(--bg-elev);border:1px solid var(--border);border-radius:16px;padding:10px 10px 10px 16px}.composer:focus-within{border-color:var(--accent-deep)}.composer textarea{flex:1;border:none;background:none;resize:none;max-height:200px;padding:6px 0;font-size:15px}.composer textarea:focus{border:none}.send-btn{width:38px;height:38px;border-radius:10px;border:none;background:var(--accent);color:#0d1117;font-size:18px;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:opacity .15s}.send-btn:disabled{opacity:.35;cursor:default}.empty{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:12px;padding:20px}.empty h1{font-size:32px;font-weight:700;letter-spacing:-1px}.empty h1 .accent{color:var(--accent)}.empty p{color:var(--text-dim);max-width:420px}.auth{height:100vh;display:flex;align-items:center;justify-content:center;padding:20px}.auth-card{width:100%;max-width:380px;background:var(--bg-elev);border:1px solid var(--border);border-radius:16px;padding:32px}.auth-card h1{font-size:28px;margin-bottom:4px;letter-spacing:-1px;display:flex;align-items:center;gap:10px}.auth-card h1 .dot{width:11px;height:11px;border-radius:50%;background:var(--accent);box-shadow:0 0 12px var(--accent)}.auth-card .sub{color:var(--text-dim);margin-bottom:24px;font-size:14px}.auth-card label{display:block;font-size:13px;color:var(--text-dim);margin:14px 0 6px}.auth-card input{width:100%}.auth-card .primary{width:100%;margin-top:22px;padding:12px;background:var(--accent);color:#0d1117;border:none;border-radius:var(--radius);font-weight:600;font-size:15px}.auth-card .primary:disabled{opacity:.5}.auth-card .switch{text-align:center;margin-top:18px;font-size:14px;color:var(--text-dim)}.auth-card .switch button{background:none;border:none;color:var(--accent);font-size:14px}.auth-card .err{color:var(--danger);font-size:14px;margin-top:14px;text-align:center}@media (max-width: 720px){.sidebar{position:fixed;z-index:20;height:100%;transform:translate(-100%);transition:transform .2s}.sidebar.open{transform:translate(0)}}