/* CSS Custom Properties - Enterprise Color Scheme */
:root {
  /* Primary Colors - Deep Blue to Charcoal Gradient */
  --primary-blue: #1e3a8a;
  --primary-charcoal: #374151;
  --accent-blue: #3b82f6;
  --light-blue: #dbeafe;
  
  /* Neutral Colors */
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-600: #4b5563;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Typography Scale */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  
  /* Spacing Scale */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* 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);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  
  /* Transitions */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--gray-800);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography Base Styles */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--gray-900);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

p {
  margin-bottom: var(--spacing-md);
  color: var(--gray-600);
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-blue);
}

/* Lists */
ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

/* Images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Container and Layout Base */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Section Styling */
.section {
  padding: var(--spacing-3xl) 0;
}

.section:nth-child(even) {
  background-color: var(--gray-50);
}

/* Grid System */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
}

/* Flexbox Utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

/* Text Alignment */
.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

/* Spacing Utilities */
.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

/* Diagram and Image Styling */
.diagram-image {
  width: 100%;
  display: block;
}

/* Metrics Display */
.metric {
  text-align: center;
  padding: var(--spacing-lg);
}

.metric h3 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--primary-blue);
  margin-bottom: var(--spacing-sm);
}

.metric p {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  margin-bottom: 0;
}

/* Focus States for Accessibility */
*:focus {
  outline: 2px solid var(--accent-blue);
  outline-offset: 2px;
}

/* Skip Link for Accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--primary-blue);
  color: var(--white);
  padding: 8px;
  text-decoration: none;
  border-radius: var(--radius-sm);
  z-index: 9999;
}

.skip-link:focus {
  top: 6px;
}

/* Utility Classes */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.hidden {
  display: none;
}

.visible {
  display: block;
}

/* Performance Optimizations */
.will-change-transform {
  will-change: transform;
}

.will-change-opacity {
  will-change: opacity;
}

/* Print Styles */
@media print {
  * {
    background: transparent !important;
    color: black !important;
    box-shadow: none !important;
    text-shadow: none !important;
  }
  
  a, a:visited {
    text-decoration: underline;
  }
  
  .nav, .hero-bg, .float-element {
    display: none;
  }
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
  :root {
    --primary-blue: #000080;
    --accent-blue: #0000ff;
    --gray-600: #000000;
    --gray-800: #000000;
    --gray-900: #000000;
  }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}