/* ============================================
   CSS Custom Properties (Design Tokens)
   ============================================ */
:root {
  /* Colors */
  --color-primary: #0066cc;
  --color-primary-dark: #004d99;
  --color-secondary: #555;
  --color-success: #28a745;
  --color-warning: #ffc107;
  --color-background: #ffffff;
  --color-text: #333;
  --color-text-light: #666;
  --color-border: #e0e0e0;
  --color-code-bg: #f5f5f5;
  
  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  
  /* Typography */
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-code: "Consolas", "Monaco", "Courier New", monospace;
  --font-size-base: 16px;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --line-height-base: 1.6;
  --line-height-heading: 1.2;
  
  /* Layout */
  --max-width-content: 1200px;
  --max-width-text: 720px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  
  /* Z-index */
  --z-header: 100;
  --z-dropdown: 200;
}

/* ============================================
   Reset & Base Styles
   ============================================ */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background: var(--color-background);
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  line-height: var(--line-height-heading);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-md);
  font-weight: 600;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
}

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

a:hover {
  color: var(--color-primary-dark);
  text-decoration: underline;
}

ul, ol {
  margin-left: var(--space-lg);
  margin-bottom: var(--space-md);
}

li {
  margin-bottom: var(--space-xs);
}

/* ============================================
   Layout
   ============================================ */
.container {
  max-width: var(--max-width-content);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.main-content {
  min-height: calc(100vh - 300px);
  padding: var(--space-lg) 0;
}

/* ============================================
   Header & Navigation
   ============================================ */
.site-header {
  background: var(--color-primary);
  color: white;
  padding: var(--space-sm) 0;
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-logo a {
  color: white;
  text-decoration: none;
  font-size: var(--font-size-xl);
  font-weight: bold;
}

.site-logo a:hover {
  text-decoration: none;
  opacity: 0.9;
}

/* Navigation */
.main-nav {
  position: relative;
}

.nav-toggle {
  display: none;
}

.nav-toggle-label {
  display: none;
  cursor: pointer;
  flex-direction: column;
  gap: 4px;
}

.nav-toggle-label span {
  display: block;
  width: 25px;
  height: 3px;
  background: white;
  transition: all var(--transition-base);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--space-md);
  margin: 0;
}

.nav-item a {
  color: white;
  text-decoration: none;
  padding: var(--space-xs) var(--space-sm);
  display: block;
  transition: background var(--transition-fast);
  border-radius: 4px;
}

.nav-item a:hover,
.nav-item.active a {
  background: var(--color-primary-dark);
  text-decoration: none;
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .nav-toggle-label {
    display: flex;
  }
  
  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    right: 0;
    background: var(--color-primary);
    width: 250px;
    padding: var(--space-sm);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    border-radius: 0 0 4px 4px;
    gap: 0;
  }
  
  .nav-toggle:checked ~ .nav-menu {
    display: flex;
  }
  
  .nav-item {
    margin: 0;
  }
  
  .nav-item a {
    padding: var(--space-sm);
  }
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
  background: var(--color-secondary);
  color: white;
  padding: var(--space-xl) 0 var(--space-lg);
  margin-top: var(--space-xl);
}

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

.footer-section h3 {
  font-size: var(--font-size-lg);
  margin-top: 0;
  margin-bottom: var(--space-sm);
}

.footer-section p {
  margin-bottom: var(--space-xs);
  font-size: var(--font-size-sm);
}

.footer-links {
  list-style: none;
  margin: 0;
}

.footer-links li {
  margin-bottom: var(--space-xs);
}

.footer-links a {
  color: white;
  text-decoration: none;
  font-size: var(--font-size-sm);
}

.footer-links a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

.footer-section a {
  color: white;
  text-decoration: underline;
}

.footer-section a:hover {
  color: var(--color-primary);
}

.cache-notice {
  font-size: var(--font-size-sm);
  color: var(--color-warning);
}

/* ============================================
   Page Content
   ============================================ */
.page {
  max-width: var(--max-width-text);
  margin: 0 auto;
}

.page-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-lg);
  border-bottom: 2px solid var(--color-border);
}

.page-header h1 {
  margin-top: 0;
}

.page-description {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ============================================
   Homepage Styles
   ============================================ */
.hero {
  text-align: center;
  padding: var(--space-xl) 0;
  margin-bottom: var(--space-xl);
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: var(--space-md);
}

.hero-tagline {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  max-width: 700px;
  margin: 0 auto var(--space-lg);
}

.hero-stats {
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
  margin-bottom: var(--space-lg);
}

.hero-stats .stat {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-primary);
}

.hero-cta {
  background: var(--color-code-bg);
  padding: var(--space-md);
  border-radius: 8px;
  margin: var(--space-lg) auto;
  max-width: 600px;
}

.hero-cta code {
  font-family: var(--font-code);
  font-size: var(--font-size-lg);
  color: var(--color-text);
}

.cta-buttons {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  margin: var(--space-xl) 0;
}

.button {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  border-radius: 6px;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-base);
}

.button.primary {
  background: var(--color-primary);
  color: white;
}

.button.primary:hover {
  background: var(--color-primary-dark);
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.button.secondary {
  background: white;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.button.secondary:hover {
  background: var(--color-primary);
  color: white;
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* ============================================
   Code Blocks
   ============================================ */
code {
  font-family: var(--font-code);
  background: var(--color-code-bg);
  padding: 0.2em 0.4em;
  border-radius: 3px;
  font-size: 0.9em;
}

pre {
  background: #1d1f21;
  padding: var(--space-md);
  border-radius: 6px;
  overflow-x: auto;
  margin: var(--space-md) 0;
}

pre code {
  background: none;
  padding: 0;
  color: #c5c8c6;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  :root {
    --font-size-base: 14px;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.5rem; }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .cta-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .button {
    width: 100%;
    max-width: 300px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-sm);
  }
  
  .hero-stats {
    flex-direction: column;
    gap: var(--space-sm);
  }
}