/* ============================================
   Design Tokens - ReceiptIQ
   Modern SaaS-inspired design system
   ============================================ */

:root {
  /* ----------------------------------------
     Color Palette
     ---------------------------------------- */

  /* Backgrounds - Deep, rich darks */
  --color-bg-primary: #0a0a0f;
  --color-bg-secondary: #12121a;
  --color-bg-tertiary: #1a1a24;
  --color-bg-elevated: #22222e;

  /* Accent Colors */
  --color-accent-primary: #6366f1;    /* Indigo */
  --color-accent-secondary: #8b5cf6;  /* Violet */
  --color-accent-tertiary: #a855f7;   /* Purple */
  --color-accent-success: #22c55e;    /* Green */
  --color-accent-warning: #f59e0b;    /* Amber */
  --color-accent-error: #ef4444;      /* Red */

  /* Text Colors */
  --color-text-primary: #f8fafc;
  --color-text-secondary: #94a3b8;
  --color-text-tertiary: #64748b;
  --color-text-muted: #475569;

  /* Border Colors */
  --color-border-subtle: rgba(255, 255, 255, 0.06);
  --color-border-default: rgba(255, 255, 255, 0.1);
  --color-border-prominent: rgba(255, 255, 255, 0.15);
  --color-border-accent: rgba(99, 102, 241, 0.5);

  /* ----------------------------------------
     Gradients
     ---------------------------------------- */
  --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
  --gradient-secondary: linear-gradient(135deg, #22c55e 0%, #10b981 100%);
  --gradient-glow: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99, 102, 241, 0.3), transparent);
  --gradient-hero-glow: radial-gradient(ellipse 60% 60% at 50% 40%, rgba(99, 102, 241, 0.15) 0%, rgba(139, 92, 246, 0.1) 30%, transparent 70%);
  --gradient-card-shine: linear-gradient(135deg, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
  --gradient-text: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);

  /* ----------------------------------------
     Shadows - Layered for depth
     ---------------------------------------- */
  --shadow-sm: 0 1px 2px 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, 0.5), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);
  --shadow-glow-lg: 0 0 60px rgba(99, 102, 241, 0.25);
  --shadow-card-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 0 40px rgba(99, 102, 241, 0.15);

  /* ----------------------------------------
     Spacing Scale (4px base)
     ---------------------------------------- */
  --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 */
  --space-32: 8rem;     /* 128px */

  /* ----------------------------------------
     Typography
     ---------------------------------------- */
  --font-family-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

  /* 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 */
  --text-7xl: 4.5rem;     /* 72px */

  /* Font Weights */
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;

  /* Line Heights */
  --line-height-none: 1;
  --line-height-tight: 1.2;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 1.75;

  /* Letter Spacing */
  --letter-spacing-tighter: -0.05em;
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  --letter-spacing-wider: 0.05em;

  /* ----------------------------------------
     Border Radius
     ---------------------------------------- */
  --radius-none: 0;
  --radius-sm: 0.375rem;  /* 6px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  --radius-2xl: 1.5rem;   /* 24px */
  --radius-3xl: 2rem;     /* 32px */
  --radius-full: 9999px;

  /* ----------------------------------------
     Transitions
     ---------------------------------------- */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slower: 500ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* ----------------------------------------
     Z-Index Scale
     ---------------------------------------- */
  --z-base: 0;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-overlay: 300;
  --z-modal: 400;
  --z-toast: 500;
  --z-max: 9999;

  /* ----------------------------------------
     Container Widths
     ---------------------------------------- */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1200px;
  --container-2xl: 1400px;
}

/* ----------------------------------------
   Dark Mode Base Styles
   ---------------------------------------- */
html {
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
}

body {
  font-family: var(--font-family-sans);
  font-size: var(--text-base);
  line-height: var(--line-height-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ----------------------------------------
   Selection Colors
   ---------------------------------------- */
::selection {
  background: rgba(99, 102, 241, 0.3);
  color: var(--color-text-primary);
}

/* ----------------------------------------
   Scrollbar Styling
   ---------------------------------------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--color-bg-elevated);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-tertiary);
}