.login-screen{position:fixed;top:0;right:0;bottom:0;left:0;z-index:1000;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#667eea,#764ba2,#06b6d4)}.login-screen.hidden{display:none}.login-card{background:#fff;border-radius:20px;padding:48px 40px;text-align:center;box-shadow:0 20px 60px #0003;max-width:380px;width:90%}.login-logo{margin-bottom:16px}.login-card h1{font-size:28px;font-weight:700;color:#1a1a2e;margin:0 0 8px}.login-card p{font-size:15px;color:#666;margin:0 0 32px}.login-btn{display:flex;align-items:center;justify-content:center;gap:10px;width:100%;padding:14px 24px;background:#fff;border:2px solid #e0e0e0;border-radius:12px;font-family:var(--font-sans);font-size:15px;font-weight:600;color:#333;cursor:pointer;transition:all .2s ease}.login-btn:hover{border-color:#4285f4;box-shadow:0 4px 16px #4285f433;transform:translateY(-1px)}.user-avatar{width:28px;height:28px;border-radius:50%;object-fit:cover}.code-editor-panel{border-top:1px solid var(--border);background:var(--bg-secondary)}.code-editor-toggle{display:flex;align-items:center;gap:8px;width:100%;padding:8px 16px;background:none;border:none;font-family:var(--font-sans);font-size:13px;font-weight:600;color:var(--text-secondary);cursor:pointer;transition:color .2s}.code-editor-toggle:hover{color:var(--text-primary)}.code-editor-chevron{margin-left:auto;transition:transform .2s ease}.code-editor-panel.open .code-editor-chevron{transform:rotate(180deg)}.code-editor-error{font-size:11px;color:#ef4444;font-weight:500}.code-editor-body{max-height:0;overflow:hidden;transition:max-height .25s ease}.code-editor-panel.open .code-editor-body{max-height:250px}#code-editor{width:100%;height:180px;padding:12px 16px;font-family:var(--font-mono);font-size:13px;line-height:1.6;color:var(--text-primary);background:var(--bg-primary);border:none;border-top:1px solid var(--border);resize:none;outline:none;-moz-tab-size:2;tab-size:2}#code-editor::placeholder{color:var(--text-tertiary);opacity:.6}#code-editor.has-error{box-shadow:inset 3px 0 #ef4444}.ai-toggle{position:relative}.ai-toggle-input{opacity:0;width:0;height:0;position:absolute}.ai-toggle-slider{display:inline-block;width:36px;height:20px;background:#ccc;border-radius:10px;position:relative;transition:background .2s;box-shadow:inset 0 1px 3px #00000026}.ai-toggle-slider:after{content:"";position:absolute;top:2px;left:2px;width:16px;height:16px;background:#fff;border-radius:50%;transition:transform .2s}.ai-toggle-input:checked+.ai-toggle-slider{background:#22c55e}.ai-toggle-input:checked+.ai-toggle-slider:after{transform:translate(16px)}.ai-toggle-input:disabled+.ai-toggle-slider{opacity:.5;cursor:not-allowed}:root{--bg-primary: #ffffff;--bg-secondary: #f7f7fa;--bg-tertiary: #eeeef4;--bg-surface: rgba(245, 245, 250, .85);--bg-surface-hover: rgba(235, 235, 245, .9);--bg-glass: rgba(255, 255, 255, .88);--text-primary: #1a1a2e;--text-secondary: #5a5a7a;--text-tertiary: #9898b0;--text-accent: #7c3aed;--accent-primary: #7c3aed;--accent-secondary: #0891b2;--accent-gradient: linear-gradient(135deg, #7c3aed, #0891b2);--accent-gradient-hover: linear-gradient(135deg, #8b5cf6, #06b6d4);--accent-glow: rgba(124, 58, 237, .15);--border-color: rgba(0, 0, 0, .07);--border-hover: rgba(0, 0, 0, .14);--success: #059669;--error: #dc2626;--warning: #d97706;--font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--font-mono: "JetBrains Mono", "Fira Code", monospace;--header-height: 56px;--chat-max-width: 720px;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 20px;--shadow-sm: 0 1px 3px rgba(0, 0, 0, .06);--shadow-md: 0 4px 12px rgba(0, 0, 0, .06);--shadow-lg: 0 8px 32px rgba(0, 0, 0, .08);--transition-fast: .15s ease;--transition-base: .25s ease;--transition-smooth: .35s cubic-bezier(.4, 0, .2, 1)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html,body{height:100%;overflow:hidden}body{font-family:var(--font-sans);font-size:14px;color:var(--text-primary);background:var(--bg-primary);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#app{display:flex;flex-direction:column;height:100vh;background:var(--bg-primary)}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#0000001f;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#0003}.app-header{display:flex;align-items:center;justify-content:space-between;height:var(--header-height);padding:0 20px;background:var(--bg-glass);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border-bottom:1px solid var(--border-color);z-index:100;flex-shrink:0}.header-left{display:flex;align-items:center;gap:12px}.logo{display:flex;align-items:center;gap:10px}.logo-text{font-size:18px;font-weight:700;background:var(--accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;letter-spacing:-.5px}.header-right{display:flex;align-items:center;gap:8px}.header-btn{display:flex;align-items:center;gap:6px;padding:8px 14px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-secondary);font-family:var(--font-sans);font-size:13px;font-weight:500;cursor:pointer;transition:all var(--transition-fast);box-shadow:var(--shadow-sm)}.header-btn:hover{background:var(--bg-surface-hover);border-color:var(--border-hover);color:var(--text-primary);box-shadow:var(--shadow-md)}.header-btn.icon-only{padding:8px}.drawer-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0003;z-index:90;opacity:0;pointer-events:none;transition:opacity .3s ease}.drawer-overlay.open{opacity:1;pointer-events:auto}.drawer{position:fixed;top:0;left:0;bottom:0;width:280px;background:var(--bg-primary);border-right:1px solid var(--border-color);z-index:100;display:flex;flex-direction:column;transform:translate(-100%);transition:transform .3s cubic-bezier(.4,0,.2,1);box-shadow:none}.drawer.open{transform:translate(0);box-shadow:8px 0 32px #0000001a}.drawer-header{padding:20px 20px 12px;border-bottom:1px solid var(--border-color)}.drawer-header h3{font-size:15px;font-weight:600;color:var(--text-primary)}.chat-list{flex:1;overflow-y:auto;padding:8px}.chat-item{display:flex;align-items:center;gap:8px;padding:10px 12px;border-radius:var(--radius-sm);cursor:pointer;transition:all var(--transition-fast);border:1px solid transparent;margin-bottom:2px}.chat-item:hover{background:var(--bg-secondary)}.chat-item.active{background:var(--bg-tertiary);border-color:var(--border-color)}.chat-item-icon{font-size:14px;flex-shrink:0;opacity:.6}.chat-item-title{flex:1;font-size:13px;color:var(--text-primary);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;line-height:1.3}.chat-item-actions{display:flex;gap:2px;opacity:0;transition:opacity var(--transition-fast)}.chat-item:hover .chat-item-actions{opacity:1}.chat-item-btn{width:26px;height:26px;display:flex;align-items:center;justify-content:center;background:none;border:none;border-radius:4px;color:var(--text-tertiary);cursor:pointer;transition:all var(--transition-fast);padding:0}.chat-item-btn:hover{background:var(--bg-secondary);color:var(--text-primary)}.chat-item-btn.delete:hover{color:var(--error)}.drawer-footer{padding:12px;border-top:1px solid var(--border-color)}.drawer-new-btn{width:100%;display:flex;align-items:center;justify-content:center;gap:8px;padding:10px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-secondary);font-family:var(--font-sans);font-size:13px;font-weight:500;cursor:pointer;transition:all var(--transition-fast)}.drawer-new-btn:hover{background:var(--bg-primary);border-color:var(--accent-primary);color:var(--accent-primary)}.main-content{display:grid;grid-template-columns:35% auto 1fr;flex:1;overflow:hidden;position:relative}.resize-handle{width:6px;cursor:col-resize;background:transparent;position:relative;z-index:10;display:flex;align-items:center;justify-content:center;transition:background var(--transition-fast);margin:0 -3px}.resize-handle:hover,.resize-handle.active{background:var(--accent-glow)}.resize-handle-bar{width:3px;height:40px;border-radius:3px;background:var(--border-color);transition:all var(--transition-fast)}.resize-handle:hover .resize-handle-bar,.resize-handle.active .resize-handle-bar{background:var(--accent-primary);height:56px}.chat-panel{display:flex;flex-direction:column;background:var(--bg-primary);overflow:hidden;min-width:280px}.chat-messages{flex:1;overflow-y:auto;padding:24px 20px;display:flex;flex-direction:column;gap:4px}.welcome-message{display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;flex:1;padding:24px;min-height:400px}.welcome-icon{margin-bottom:20px;animation:float 3s ease-in-out infinite}@keyframes float{0%,to{transform:translateY(0)}50%{transform:translateY(-8px)}}.welcome-message h2{font-size:22px;font-weight:600;margin-bottom:8px;background:var(--accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.welcome-message p{color:var(--text-secondary);font-size:14px;max-width:340px;line-height:1.5}.example-prompts{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:28px;width:100%;max-width:420px}.example-prompt{display:flex;align-items:center;gap:8px;padding:12px 14px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-md);color:var(--text-secondary);font-family:var(--font-sans);font-size:12.5px;font-weight:400;cursor:pointer;transition:all var(--transition-fast);text-align:left;box-shadow:var(--shadow-sm)}.example-prompt:hover{background:var(--bg-primary);border-color:var(--accent-primary);color:var(--text-primary);transform:translateY(-1px);box-shadow:0 4px 12px #7c3aed1a}.example-icon{font-size:16px;flex-shrink:0}.message{display:flex;gap:12px;padding:14px 16px;border-radius:var(--radius-md);animation:messageIn .3s var(--transition-smooth);max-width:100%}@keyframes messageIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.message-avatar{width:30px;height:30px;border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;flex-shrink:0;font-size:14px}.message-avatar.user{background:var(--accent-gradient);color:#fff;font-weight:600}.message-avatar.assistant{background:var(--bg-tertiary);border:1px solid var(--border-color)}.message-body{flex:1;min-width:0;overflow:hidden}.message-body p{line-height:1.6;word-wrap:break-word}.message-body pre{background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-sm);padding:12px;overflow-x:auto;margin:8px 0;font-family:var(--font-mono);font-size:12px;line-height:1.5}.message-body code{font-family:var(--font-mono);font-size:12.5px;background:var(--bg-tertiary);padding:2px 6px;border-radius:4px;color:var(--accent-primary)}.message-body pre code{background:none;padding:0;color:inherit}.message.user{background:#7c3aed0d}.message.assistant{background:transparent}.typing-indicator{display:flex;gap:5px;padding:4px 0}.typing-indicator span{width:7px;height:7px;border-radius:50%;background:var(--accent-primary);animation:typingBounce 1.4s ease-in-out infinite}.typing-indicator span:nth-child(2){animation-delay:.2s}.typing-indicator span:nth-child(3){animation-delay:.4s}@keyframes typingBounce{0%,60%,to{transform:translateY(0);opacity:.3}30%{transform:translateY(-8px);opacity:1}}.chat-input-container{padding:16px 20px;border-top:1px solid var(--border-color);background:var(--bg-glass);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px)}.chat-input-wrapper{display:flex;align-items:flex-end;gap:8px;background:var(--bg-primary);border:1px solid var(--border-color);border-radius:var(--radius-md);padding:6px 8px 6px 16px;transition:border-color var(--transition-fast),box-shadow var(--transition-fast);box-shadow:var(--shadow-sm)}.chat-input-wrapper:focus-within{border-color:var(--accent-primary);box-shadow:0 0 0 3px var(--accent-glow)}#chat-input{flex:1;background:none;border:none;outline:none;color:var(--text-primary);font-family:var(--font-sans);font-size:14px;line-height:1.5;resize:none;max-height:140px;padding:6px 0}#chat-input::placeholder{color:var(--text-tertiary)}.btn-send{width:36px;height:36px;display:flex;align-items:center;justify-content:center;border:none;border-radius:var(--radius-sm);background:var(--accent-gradient);color:#fff;cursor:pointer;flex-shrink:0;transition:all var(--transition-fast);opacity:.4}.btn-send:not(:disabled){opacity:1}.btn-send:not(:disabled):hover{background:var(--accent-gradient-hover);transform:scale(1.05);box-shadow:0 4px 16px 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var(--transition-fast)}.tab-btn:hover{color:var(--text-secondary)}.tab-btn.active{background:var(--bg-primary);color:var(--text-primary);box-shadow:var(--shadow-sm)}.diagram-actions{display:flex;align-items:center;gap:4px;flex-wrap:wrap}.action-btn{display:flex;align-items:center;gap:5px;padding:6px 8px;background:transparent;border:1px solid transparent;border-radius:6px;color:var(--text-tertiary);font-family:var(--font-sans);font-size:12px;font-weight:500;cursor:pointer;transition:all var(--transition-fast)}.action-btn:hover{background:var(--bg-primary);border-color:var(--border-color);color:var(--text-primary);box-shadow:var(--shadow-sm)}.action-label{font-size:11px;font-weight:600;letter-spacing:.5px;text-transform:uppercase}.action-divider{width:1px;height:20px;background:var(--border-color);margin:0 4px}.diagram-content{flex:1;position:relative;overflow:hidden}.diagram-preview{position:absolute;top:0;right:0;bottom:0;left:0;display:none;overflow:auto;padding:200px;align-items:flex-start;justify-content:center;background:#fff}.diagram-preview.active{display:flex}.diagram-preview svg{max-width:100%;height:auto}.diagram-empty{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:16px;color:var(--text-tertiary);font-size:14px;-webkit-user-select:none;user-select:none;height:100%}.diagram-code{position:absolute;top:0;right:0;bottom:0;left:0;display:none;overflow:auto;padding:20px;background:var(--bg-primary)}.diagram-code.active{display:block}.diagram-code pre{margin:0;font-family:var(--font-mono);font-size:13px;line-height:1.7;color:var(--text-primary);white-space:pre-wrap;word-break:break-word}.copy-code-btn{position:absolute;top:12px;right:12px;display:flex;align-items:center;gap:6px;padding:6px 10px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:6px;color:var(--text-secondary);font-family:var(--font-sans);font-size:12px;cursor:pointer;transition:all var(--transition-fast);box-shadow:var(--shadow-sm)}.copy-code-btn:hover{background:var(--bg-primary);color:var(--text-primary);box-shadow:var(--shadow-md)}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000040;backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);display:none;align-items:center;justify-content:center;z-index:1000;animation:fadeIn .2s ease}.modal-overlay.active{display:flex}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}.modal{background:var(--bg-primary);border:1px solid var(--border-color);border-radius:var(--radius-lg);width:92%;max-width:440px;box-shadow:0 24px 64px #00000026;animation:modalSlideIn .3s var(--transition-smooth)}@keyframes modalSlideIn{0%{opacity:0;transform:translateY(-16px) scale(.96)}to{opacity:1;transform:translateY(0) scale(1)}}.modal-header{display:flex;align-items:center;justify-content:space-between;padding:20px 24px 0}.modal-header h3{font-size:17px;font-weight:600}.modal-close{background:none;border:none;color:var(--text-tertiary);cursor:pointer;padding:4px;border-radius:6px;transition:all var(--transition-fast)}.modal-close:hover{background:var(--bg-tertiary);color:var(--text-primary)}.modal-body{padding:24px;display:flex;flex-direction:column;gap:20px}.setting-group{display:flex;flex-direction:column;gap:6px}.setting-group label{font-size:13px;font-weight:500;color:var(--text-secondary)}.setting-group input,.setting-group select{padding:10px 14px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-primary);font-family:var(--font-sans);font-size:14px;outline:none;transition:all var(--transition-fast);-moz-appearance:none;appearance:none;-webkit-appearance:none}.setting-group select{background-image:url("data:image/svg+xml,%3Csvg 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var(--accent-glow);transform:translateY(-1px)}.toast{position:fixed;bottom:32px;left:50%;transform:translate(-50%) translateY(80px);padding:10px 20px;background:var(--bg-primary);border:1px solid var(--border-color);border-radius:var(--radius-sm);color:var(--text-primary);font-size:13px;font-weight:500;box-shadow:var(--shadow-lg);z-index:2000;opacity:0;pointer-events:none;transition:all .35s cubic-bezier(.4,0,.2,1)}.toast.visible{opacity:1;transform:translate(-50%) translateY(0)}.toast.success{border-color:var(--success);box-shadow:0 8px 32px #0596691a}.toast.error{border-color:var(--error);box-shadow:0 8px 32px #dc26261a}@media(max-width:768px){.main-content{grid-template-columns:1fr;grid-template-rows:1fr 1fr}.resize-handle{display:none}.chat-panel{border-right:none;border-bottom:1px solid var(--border-color)}.example-prompts{grid-template-columns:1fr}.diagram-actions .action-label{display:none}}