/* ============================================
   CSS VARIABLES - DESIGN SYSTEM
   ============================================ */

:root {
  /* ========== COLORS ========== */
  
  /* Primary Colors - Construction Theme */
  --primary-color: #FF6B35;
  --primary-dark: #E55A2B;
  --primary-light: #FFE5DC;
  --primary-hover: #FF5722;
  
  /* Secondary Colors - Trust & Reliability */
  --secondary-color: #004E89;
  --secondary-dark: #003A66;
  --secondary-light: #E6F2FF;
  --secondary-hover: #00639B;
  
  /* Neutral Colors */
  --text-primary: #1A1A1A;
  --text-secondary: #666666;
  --text-light: #999999;
  --background: #FFFFFF;
  --background-alt: #F5F5F5;
  --background-dark: #1A1A1A;
  --border: #E0E0E0;
  --border-light: #F0F0F0;
  
  /* Accent Colors */
  --accent-yellow: #FFC107;
  --accent-yellow-dark: #FFA000;
  --success: #4CAF50;
  --error: #F44336;
  --warning: #FF9800;
  --info: #2196F3;
  
  /* ========== TYPOGRAPHY ========== */
  
  /* Font Families */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-heading: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  /* Font Sizes */
  --text-xs: 0.75rem;      /* 12px */
  --text-sm: 0.875rem;     /* 14px */
  --text-base: 1rem;       /* 16px - minimum for readability */
  --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 */
  
  /* Line Heights */
  --leading-none: 1;
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  --leading-loose: 2;
  
  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;
  
  /* ========== SPACING ========== */
  
  /* Spacing Scale (8px base) */
  --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 */
  
  /* ========== LAYOUT ========== */
  
  /* Container Widths */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1536px;
  
  /* Max Width */
  --max-width: 1280px;
  
  /* ========== BORDERS ========== */
  
  /* Border Radius */
  --radius-none: 0;
  --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;
  
  /* Border Widths */
  --border-width: 1px;
  --border-width-2: 2px;
  --border-width-4: 4px;
  
  /* ========== SHADOWS ========== */
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
  
  /* ========== TRANSITIONS ========== */
  
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* ========== Z-INDEX SCALE ========== */
  
  --z-base: 1;
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
  
  /* ========== BREAKPOINTS (for reference) ========== */
  /* Use in media queries:
     Mobile: 320px - 767px
     Tablet: 768px - 1023px
     Desktop: 1024px+
  */
}

/* ============================================
   DARK MODE SUPPORT (Optional)
   ============================================ */

@media (prefers-color-scheme: dark) {
  :root {
    /* Uncomment to enable dark mode */
    /* --text-primary: #FFFFFF;
    --text-secondary: #CCCCCC;
    --background: #1A1A1A;
    --background-alt: #2A2A2A;
    --border: #404040; */
  }
}

/* ============================================
   UTILITY CLASSES FOR COMMON PATTERNS
   ============================================ */

/* High Contrast Text Combinations */
.text-on-light {
  color: var(--text-primary);
  background: var(--background);
}

.text-on-dark {
  color: var(--background);
  background: var(--text-primary);
}

.text-on-primary {
  color: var(--background);
  background: var(--primary-color);
}

.text-on-secondary {
  color: var(--background);
  background: var(--secondary-color);
}

/* Ensure minimum contrast ratios (WCAG AA) */
/* Light backgrounds require dark text */
/* Dark backgrounds require light text */
/* Colored backgrounds require white text */