/* ============================================
   EduTools - CSS Design System Variables
   ============================================ */

:root {
  /* === Primary Colors === */
  --primary-50: #EEF2FF;
  --primary-100: #E0E7FF;
  --primary-200: #C7D2FE;
  --primary-300: #A5B4FC;
  --primary-400: #818CF8;
  --primary-500: #6366F1;
  --primary-600: #4F46E5;
  --primary-700: #4338CA;
  --primary-800: #3730A3;
  --primary-900: #312E81;
  
  /* === Secondary Colors (Teal) === */
  --secondary-50: #F0FDFA;
  --secondary-100: #CCFBF1;
  --secondary-200: #99F6E4;
  --secondary-300: #5EEAD4;
  --secondary-400: #2DD4BF;
  --secondary-500: #14B8A6;
  --secondary-600: #0D9488;
  --secondary-700: #0F766E;
  --secondary-800: #115E59;
  --secondary-900: #134E4A;
  
  /* === Accent Colors (Amber) === */
  --accent-50: #FFFBEB;
  --accent-100: #FEF3C7;
  --accent-200: #FDE68A;
  --accent-300: #FCD34D;
  --accent-400: #FBBF24;
  --accent-500: #F59E0B;
  --accent-600: #D97706;
  --accent-700: #B45309;
  --accent-800: #92400E;
  --accent-900: #78350F;
  
  /* === Success (Green) === */
  --success-50: #ECFDF5;
  --success-100: #D1FAE5;
  --success-500: #10B981;
  --success-600: #059669;
  --success-700: #047857;
  
  /* === Warning (Orange) === */
  --warning-50: #FFF7ED;
  --warning-100: #FFEDD5;
  --warning-500: #F97316;
  --warning-600: #EA580C;
  
  /* === Error (Red) === */
  --error-50: #FEF2F2;
  --error-100: #FEE2E2;
  --error-500: #EF4444;
  --error-600: #DC2626;
  
  /* === Neutral Colors === */
  --neutral-50: #F8FAFC;
  --neutral-100: #F1F5F9;
  --neutral-200: #E2E8F0;
  --neutral-300: #CBD5E1;
  --neutral-400: #94A3B8;
  --neutral-500: #64748B;
  --neutral-600: #475569;
  --neutral-700: #334155;
  --neutral-800: #1E293B;
  --neutral-900: #0F172A;
  
  /* === Background & Surface === */
  --bg-primary: #F8FAFC;
  --bg-secondary: #FFFFFF;
  --bg-tertiary: #F1F5F9;
  --surface-card: #FFFFFF;
  --surface-elevated: #FFFFFF;
  
  /* === Text Colors === */
  --text-primary: #1E293B;
  --text-secondary: #64748B;
  --text-tertiary: #94A3B8;
  --text-inverse: #FFFFFF;
  --text-link: #4F46E5;
  --text-link-hover: #4338CA;
  
  /* === Border Colors === */
  --border-light: #E2E8F0;
  --border-default: #CBD5E1;
  --border-dark: #94A3B8;
  --border-focus: #6366F1;
  
  /* === Category Colors === */
  --cat-matematik: #6366F1;
  --cat-fen: #10B981;
  --cat-fizik: #3B82F6;
  --cat-kimya: #8B5CF6;
  --cat-biyoloji: #22C55E;
  --cat-turkce: #EF4444;
  --cat-ingilizce: #F59E0B;
  --cat-tarih: #B45309;
  --cat-cografya: #0EA5E9;
  --cat-kodlama: #EC4899;
  --cat-sanat: #F472B6;
  --cat-muzik: #A855F7;
  --cat-stem: #14B8A6;
  
  /* === Pricing Colors === */
  --price-free: #10B981;
  --price-freemium: #F59E0B;
  --price-paid: #EF4444;
  
  /* === Gradients === */
  --gradient-primary: linear-gradient(135deg, #6366F1 0%, #8B5CF6 100%);
  --gradient-secondary: linear-gradient(135deg, #14B8A6 0%, #0EA5E9 100%);
  --gradient-accent: linear-gradient(135deg, #F59E0B 0%, #F97316 100%);
  --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-card-hover: linear-gradient(180deg, rgba(99, 102, 241, 0.05) 0%, rgba(139, 92, 246, 0.05) 100%);
  
  /* === Typography === */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-display: 'Outfit', 'Inter', sans-serif;
  
  /* Font Sizes */
  --text-xs: 0.75rem;      /* 12px */
  --text-sm: 0.875rem;     /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg: 1.125rem;     /* 18px */
  --text-xl: 1.25rem;      /* 20px */
  --text-2xl: 1.5rem;      /* 24px */
  --text-3xl: 1.875rem;    /* 30px */
  --text-4xl: 2.25rem;     /* 36px */
  --text-5xl: 3rem;        /* 48px */
  --text-6xl: 3.75rem;     /* 60px */
  
  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;
  
  /* Line Heights */
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  
  /* === Spacing === */
  --space-0: 0;
  --space-1: 0.25rem;      /* 4px */
  --space-2: 0.5rem;       /* 8px */
  --space-3: 0.75rem;      /* 12px */
  --space-4: 1rem;         /* 16px */
  --space-5: 1.25rem;      /* 20px */
  --space-6: 1.5rem;       /* 24px */
  --space-8: 2rem;         /* 32px */
  --space-10: 2.5rem;      /* 40px */
  --space-12: 3rem;        /* 48px */
  --space-16: 4rem;        /* 64px */
  --space-20: 5rem;        /* 80px */
  --space-24: 6rem;        /* 96px */
  
  /* === Border Radius === */
  --radius-sm: 0.25rem;    /* 4px */
  --radius-md: 0.5rem;     /* 8px */
  --radius-lg: 0.75rem;    /* 12px */
  --radius-xl: 1rem;       /* 16px */
  --radius-2xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;
  
  /* === Shadows === */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-card-hover: 0 12px 40px rgba(99, 102, 241, 0.15);
  
  /* === Transitions === */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
  --transition-bounce: 300ms cubic-bezier(0.34, 1.56, 0.64, 1);
  
  /* === Z-Index === */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
  
  /* === Container Widths === */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1536px;
  
  /* === Breakpoints (for reference in JS) === */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;
}

/* === Dark Theme === */
[data-theme="dark"] {
  /* Background & Surface */
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-tertiary: #1E293B;
  --surface-card: #1E293B;
  --surface-elevated: #334155;
  
  /* Text Colors */
  --text-primary: #F1F5F9;
  --text-secondary: #94A3B8;
  --text-tertiary: #64748B;
  --text-inverse: #0F172A;
  --text-link: #818CF8;
  --text-link-hover: #A5B4FC;
  
  /* Border Colors */
  --border-light: #334155;
  --border-default: #475569;
  --border-dark: #64748B;
  --border-focus: #818CF8;
  
  /* Neutral Colors Override */
  --neutral-50: #1E293B;
  --neutral-100: #334155;
  --neutral-200: #475569;
  --neutral-300: #64748B;
  --neutral-800: #E2E8F0;
  --neutral-900: #F1F5F9;
  
  /* Shadows for Dark Mode */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4), 0 1px 2px -1px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-card-hover: 0 12px 40px rgba(99, 102, 241, 0.25);
  
  /* Gradients for Dark Mode */
  --gradient-card-hover: linear-gradient(180deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
}

/* Theme Transition */
html {
  transition: background-color 0.3s ease, color 0.3s ease;
}

body, .navbar, .footer, .tool-card, .category-card, .section {
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}