*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}:root{--bg-primary: #1a1a2e;--bg-secondary: #16213e;--bg-sidebar: #0f1629;--bg-input: #1e2a45;--bg-hover: #1e2a45;--bg-bubble-user: #2563eb;--bg-bubble-ai: #1e2a45;--bg-code: #0d1117;--text-primary: #e2e8f0;--text-secondary: #94a3b8;--text-muted: #64748b;--text-accent: #818cf8;--border-color: #2d3a5c;--border-input: #374768;--shadow: 0 4px 24px rgba(0, 0, 0, .3);--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-full: 9999px;--sidebar-width: 280px;--header-height: 60px;--input-area-height: auto;--font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;--font-mono: "SF Mono", "Fira Code", "Cascadia Code", monospace}html,body{height:100%;width:100%;overflow:hidden;font-family:var(--font-family);background:var(--bg-primary);color:var(--text-primary);font-size:15px;line-height:1.6}#app{height:100%;width:100%}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--border-color);border-radius:3px}::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}.sidebar{width:var(--sidebar-width);height:100vh;background:var(--bg-sidebar);border-right:1px solid var(--border-color);display:flex;flex-direction:column;flex-shrink:0;transition:transform .3s ease;z-index:100}.sidebar-header{padding:16px;display:flex;align-items:center;gap:8px}.new-chat-btn{flex:1;display:flex;align-items:center;justify-content:center;gap:8px;padding:10px 16px;background:linear-gradient(135deg,#4f46e5,#7c3aed);color:#fff;border:none;border-radius:var(--radius-sm);cursor:pointer;font-size:14px;font-weight:500;transition:opacity .2s}.new-chat-btn:hover{opacity:.9}.sidebar-close-btn{display:none;align-items:center;justify-content:center;width:36px;height:36px;background:transparent;border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-secondary);cursor:pointer}.session-list{flex:1;overflow-y:auto;padding:8px}.session-item{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:var(--radius-sm);cursor:pointer;transition:background .2s;color:var(--text-secondary);font-size:13px;margin-bottom:2px}.session-item:hover,.session-item.active{background:var(--bg-hover);color:var(--text-primary)}.session-title{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.delete-btn{opacity:0;display:flex;align-items:center;justify-content:center;background:transparent;border:none;color:var(--text-muted);cursor:pointer;padding:4px;border-radius:4px;transition:all .2s}.session-item:hover .delete-btn{opacity:1}.delete-btn:hover{color:#ef4444;background:#ef44441a}.sidebar-footer{padding:16px;border-top:1px solid var(--border-color)}.powered-by{text-align:center;font-size:12px;color:var(--text-muted)}.sidebar-overlay{display:none;position:fixed;top:0;right:0;bottom:0;left:0;background:#00000080;z-index:90}.chat-view{flex:1;display:flex;flex-direction:column;height:100vh;min-width:0;background:var(--bg-primary)}.chat-header{height:var(--header-height);display:flex;align-items:center;padding:0 20px;border-bottom:1px solid var(--border-color);flex-shrink:0}.menu-btn{display:none;align-items:center;justify-content:center;width:40px;height:40px;background:transparent;border:none;color:var(--text-secondary);cursor:pointer;border-radius:var(--radius-sm);margin-right:8px}.menu-btn:hover{background:var(--bg-hover)}.chat-title{font-size:18px;font-weight:600;background:linear-gradient(135deg,#818cf8,#c084fc);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.header-spacer{flex:1}.header-user{display:flex;align-items:center;gap:10px}.user-avatar{width:28px;height:28px;border-radius:50%;object-fit:cover}.user-name{font-size:13px;color:var(--text-secondary);max-width:120px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.login-btn{display:flex;align-items:center;gap:6px;padding:6px 14px;background:var(--bg-input);border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-secondary);cursor:pointer;font-size:13px;font-family:var(--font-family);transition:all .2s}.login-btn:hover{background:var(--bg-hover);color:var(--text-primary);border-color:var(--text-accent)}.logout-btn{padding:4px 10px;background:transparent;border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-muted);cursor:pointer;font-size:12px;font-family:var(--font-family);transition:all .2s}.logout-btn:hover{color:#ef4444;border-color:#ef4444}.login-error-msg{font-size:12px;color:#ef4444;max-width:300px}.message-list{flex:1;overflow-y:auto;padding:20px}.welcome-screen{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;gap:16px;color:var(--text-secondary)}.welcome-icon{color:var(--text-accent);opacity:.6;margin-bottom:8px}.welcome-screen h2{font-size:28px;font-weight:600;color:var(--text-primary)}.welcome-screen p{font-size:15px;color:var(--text-muted)}.suggestions{display:flex;flex-wrap:wrap;gap:10px;margin-top:24px;max-width:600px;justify-content:center}.suggestion-chip{padding:10px 18px;background:var(--bg-input);border:1px solid var(--border-color);border-radius:var(--radius-full);color:var(--text-secondary);cursor:pointer;font-size:13px;transition:all .2s}.suggestion-chip:hover{background:var(--bg-hover);color:var(--text-primary);border-color:var(--text-accent)}.messages-container{max-width:800px;margin:0 auto;display:flex;flex-direction:column;gap:20px;padding-bottom:20px}.message-bubble{display:flex;gap:12px;animation:fadeInUp .3s ease}@keyframes fadeInUp{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.bubble-avatar{width:36px;height:36px;border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;flex-shrink:0}.message-bubble.user .bubble-avatar{background:var(--bg-bubble-user);color:#fff}.message-bubble.assistant .bubble-avatar{background:linear-gradient(135deg,#4f46e5,#7c3aed);color:#fff}.bubble-content{flex:1;min-width:0}.bubble-header{font-size:12px;font-weight:600;color:var(--text-muted);margin-bottom:4px;text-transform:uppercase;letter-spacing:.5px}.bubble-text{font-size:15px;line-height:1.7;color:var(--text-primary);word-break:break-word}.bubble-text p{margin-bottom:8px}.bubble-text p:last-child{margin-bottom:0}.bubble-text h1,.bubble-text h2,.bubble-text h3{margin-top:16px;margin-bottom:8px;color:var(--text-primary)}.bubble-text ul,.bubble-text ol{padding-left:24px;margin:8px 0}.bubble-text li{margin-bottom:4px}.bubble-text a{color:var(--text-accent);text-decoration:none}.bubble-text a:hover{text-decoration:underline}.bubble-text .code-block{background:var(--bg-code);border:1px solid var(--border-color);border-radius:var(--radius-sm);padding:16px;overflow-x:auto;margin:12px 0;font-family:var(--font-mono);font-size:13px;line-height:1.5}.bubble-text 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var(--border-color);flex-shrink:0;background:var(--bg-primary)}.chat-input-wrapper{max-width:800px;margin:0 auto;display:flex;align-items:flex-end;gap:12px;background:var(--bg-input);border:1px solid var(--border-input);border-radius:var(--radius-md);padding:8px 8px 8px 16px;transition:border-color .2s}.chat-input-wrapper:focus-within{border-color:var(--text-accent)}.chat-input{flex:1;background:transparent;border:none;color:var(--text-primary);font-size:15px;font-family:var(--font-family);line-height:1.5;resize:none;outline:none;max-height:200px;padding:6px 0}.chat-input::placeholder{color:var(--text-muted)}.send-btn{width:40px;height:40px;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#4f46e5,#7c3aed);border:none;border-radius:var(--radius-sm);color:#fff;cursor:pointer;flex-shrink:0;transition:all .2s}.send-btn:hover:not(:disabled){opacity:.9;transform:scale(1.05)}.send-btn:disabled{opacity:.4;cursor:not-allowed}.input-footer{text-align:center;font-size:12px;color:var(--text-muted);margin-top:8px}@media (max-width: 768px){.sidebar{position:fixed;left:0;top:0;transform:translate(-100%)}.sidebar.open{transform:translate(0)}.sidebar-close-btn{display:flex}.sidebar-overlay.show{display:block}.menu-btn{display:flex}.message-list{padding:16px 12px}.chat-input-container{padding:12px}.suggestions{flex-direction:column;align-items:stretch}}.app{display:flex;height:100vh;width:100vw;overflow:hidden}