/* Design Tokens - CSS Custom Properties */

:root {
  /* ========================
     COLOR PALETTE
     ======================== */

  /* Neutral Foundation - Gray Scale */
  --gray-50:   #FAFBFC;
  --gray-100:  #F4F5F7;
  --gray-200:  #E5E7EB;
  --gray-300:  #D1D5DB;
  --gray-400:  #9CA3AF;
  --gray-500:  #6B7280;
  --gray-600:  #4B5563;
  --gray-700:  #374151;
  --gray-800:  #1F2937;
  --gray-900:  #111827;

  /* Brand Blues - Professional, Trustworthy */
  --blue-50:   #EEF2FF;
  --blue-100:  #E0E7FF;
  --blue-500:  #6366F1;
  --blue-600:  #4F46E5;
  --blue-700:  #4338CA;
  --blue-900:  #312E81;

  /* Semantic Colors */
  --success:       #10B981;
  --success-light: #D1FAE5;
  --success-dark:  #065F46;
  --warning:       #F59E0B;
  --warning-light: #FEF3C7;
  --warning-dark:  #92400E;
  --danger:        #EF4444;
  --danger-light:  #FEE2E2;
  --danger-dark:   #991B1B;
  --info:          #3B82F6;
  --info-light:    #DBEAFE;
  --info-dark:     #1E40AF;

  /* ========================
     TYPOGRAPHY
     ======================== */

  /* Font Stacks */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI',
               'Noto Sans', Helvetica, Arial, sans-serif,
               'Apple Color Emoji', 'Segoe UI Emoji';
  --font-mono: ui-monospace, 'SF Mono', 'Cascadia Code',
               'Source Code Pro', Menlo, Monaco,
               'Courier New', monospace;

  /* Type Scale */
  --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 */

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

  /* Line Heights */
  --leading-tight:   1.25;
  --leading-normal:  1.5;
  --leading-relaxed: 1.625;

  /* ========================
     SPACING
     ======================== */

  --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 */

  /* ========================
     LAYOUT
     ======================== */

  /* Container Widths */
  --container-sm:  640px;
  --container-md:  768px;
  --container-lg:  1024px;
  --container-xl:  1280px;
  --container-2xl: 1400px;

  /* Breakpoints (for reference - use in media queries) */
  /* --bp-xs: 320px;   Phone portrait */
  /* --bp-sm: 640px;   Phone landscape / small tablet */
  /* --bp-md: 768px;   Tablet portrait */
  /* --bp-lg: 1024px;  Tablet landscape / small desktop */
  /* --bp-xl: 1280px;  Desktop */

  /* Touch target minimum (WCAG 2.5.5) */
  --touch-target-min: 44px;

  /* Border Radius */
  --radius-sm:  4px;
  --radius-md:  6px;
  --radius-lg:  8px;
  --radius-xl:  12px;
  --radius-2xl: 16px;
  --radius-full: 9999px;

  /* ========================
     SHADOWS
     ======================== */

  --shadow-sm:  0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md:  0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg:  0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl:  0 20px 25px rgba(0, 0, 0, 0.1);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);

  /* ========================
     TRANSITIONS
     ======================== */

  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out:    cubic-bezier(0.0, 0, 0.2, 1);
  --ease-in:     cubic-bezier(0.4, 0, 1, 1);
  --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

  --duration-fast:   150ms;
  --duration-normal: 200ms;
  --duration-slow:   300ms;

  /* ========================
     Z-INDEX SCALE
     ======================== */

  --z-base:    0;
  --z-above:   10;
  --z-dropdown: 100;
  --z-sticky:  200;
  --z-modal:   300;
  --z-toast:   400;
  --z-tooltip: 500;
}

/* Dark Mode Support (Future Enhancement) */
@media (prefers-color-scheme: dark) {
  :root {
    /* Uncomment when implementing dark mode
    --bg-primary: var(--gray-900);
    --bg-secondary: var(--gray-800);
    --text-primary: var(--gray-50);
    --text-secondary: var(--gray-300);
    */
  }
}