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summary{cursor:pointer;font-weight:var(--font-weight-semibold);color:var(--text-dark);margin-bottom:var(--spacing-sm)}.error-stack{font-family:var(--font-family-mono);font-size:var(--font-size-sm);color:var(--error-main);white-space:pre-wrap;word-break:break-word;margin-top:var(--spacing-sm);padding:var(--spacing-sm);background:var(--bg-white);border-radius:var(--radius-sm);overflow-x:auto}.error-actions{display:flex;gap:var(--spacing-md);justify-content:center;margin-top:var(--spacing-xl)}@media (max-width: 768px){.error-boundary-content{padding:var(--spacing-xl)}.error-title{font-size:var(--font-size-2xl)}.error-actions{flex-direction:column}.error-actions .btn{width:100%}}*{margin:0;padding:0;box-sizing:border-box}:root{--primary-physics: #3B82F6;--primary-chemistry: #F59E0B;--primary-biology: #10B981;--primary-math: #8B5CF6;--primary-physics-light: #60A5FA;--primary-physics-dark: #2563EB;--primary-chemistry-light: #FBBF24;--primary-chemistry-dark: #D97706;--primary-biology-light: #34D399;--primary-biology-dark: #059669;--primary-math-light: #A78BFA;--primary-math-dark: #7C3AED;--gray-50: #F9FAFB;--gray-100: #F3F4F6;--gray-200: #E5E7EB;--gray-300: #D1D5DB;--gray-400: #9CA3AF;--gray-500: #6B7280;--gray-600: #4B5563;--gray-700: #374151;--gray-800: #1F2937;--gray-900: #111827;--bg-light: var(--gray-50);--bg-white: #FFFFFF;--bg-dark: #0F172A;--text-dark: var(--gray-900);--text-medium: var(--gray-700);--text-light: var(--gray-500);--text-lighter: var(--gray-400);--border-light: var(--gray-200);--border-medium: var(--gray-300);--border-dark: var(--gray-400);--success-main: #10B981;--success-light: #D1FAE5;--success-dark: #059669;--warning-main: #F59E0B;--warning-light: #FEF3C7;--warning-dark: #D97706;--error-main: #EF4444;--error-light: #FEE2E2;--error-dark: #DC2626;--info-main: #3B82F6;--info-light: #DBEAFE;--info-dark: #2563EB;--primary-main: var(--primary-physics);--spacing-xs: 4px;--spacing-sm: 8px;--spacing-md: 16px;--spacing-lg: 24px;--spacing-xl: 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