/* =========================================
   Global Design Tokens (Apple Style)
   ========================================= */
:root {
  /* Colors */
  --color-primary: #0066cc; /* Action Blue */
  --color-primary-active: #0071e3;
  --color-ink: #1d1d1f;
  --color-ink-muted: #7a7a7a;
  --color-ink-footer: #333333;
  --color-canvas: #ffffff;
  --color-parchment: #f5f5f7;
  --color-surface-black: #000000;
  --color-hairline: #e0e0e0;

  /* Typography */
  --font-display: "SF Pro Display", system-ui, -apple-system, sans-serif;
  --font-body: "SF Pro Text", system-ui, -apple-system, sans-serif;
  
  /* Spacing */
  --spacing-sm: 12px;
  --spacing-md: 17px;
  --spacing-lg: 24px;
  --spacing-section: 80px;

  /* Border Radius */
  --rounded-lg: 18px;
  --rounded-pill: 9999px;
}

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

body {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.47;
  letter-spacing: -0.374px;
  color: var(--color-ink);
  background-color: var(--color-canvas);
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  
  /* Adjusted padding: only makes room for the floating global-nav now */
  padding-top: 100px; 
}

main { 
  flex: 1; 
}

/* =========================================
   Navigation
   ========================================= */
/* Global Top Navigation - Floating Glass Pill */
.global-nav {
  position: fixed;
  top: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  
  /* Glassmorphism Effect */
  background-color: rgba(255, 255, 255, 0.75);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  
  border-radius: var(--rounded-pill);
  height: 52px;
  display: flex;
  align-items: center;
  padding: 0 var(--spacing-lg);
  width: max-content;
  max-width: 95vw;
  overflow-x: auto;
  
  /* Hide scrollbars for cleaner look on small screens */
  scrollbar-width: none; 
}

.global-nav::-webkit-scrollbar {
  display: none;
}

.global-nav a {
  color: var(--color-ink);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: -0.12px;
  margin-right: 20px;
  white-space: nowrap;
  transition: color 0.2s ease;
}

.global-nav a:last-child {
  margin-right: 0;
}

.global-nav a:hover {
  color: var(--color-primary);
}

/* Sub Navigation (Static, centered, no background) */
.sub-nav {
  /* Removed position: fixed so it stays in document flow and scrolls away */
  display: flex;
  justify-content: center; /* Centers the title */
  align-items: center;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  
  background-color: transparent;
  border-bottom: none;
}

.sub-nav-title {
  font-family: var(--font-display);
  font-size: 34px; /* Made bigger */
  font-weight: 700; /* Made bolder */
  letter-spacing: 0.231px;
}

/* =========================================
   Footer
   ========================================= */
.global-footer {
  background-color: var(--color-parchment);
  color: var(--color-ink-footer);
  padding: 64px var(--spacing-lg);
  font-size: 12px;
  text-align: center;
  border-top: 1px solid var(--color-hairline);
}

/* =========================================
   Typography & Content Layout
   ========================================= */
h1 { 
  font-family: var(--font-display); 
  font-size: 56px; 
  font-weight: 600; 
  line-height: 1.07; 
  letter-spacing: -0.28px; 
  margin-bottom: var(--spacing-md); 
}

h2 { 
  font-family: var(--font-display); 
  font-size: 40px; 
  font-weight: 600; 
  line-height: 1.1; 
  margin-bottom: var(--spacing-sm); 
}

h3 { 
  font-family: var(--font-display); 
  font-size: 28px; 
  font-weight: 400; 
  margin-top: var(--spacing-lg); 
  margin-bottom: var(--spacing-sm); 
}

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

ul { 
  margin-left: var(--spacing-lg); 
  margin-bottom: var(--spacing-lg); 
}

li { 
  margin-bottom: 8px; 
}

pre {
  background-color: var(--color-parchment);
  padding: var(--spacing-lg);
  border-radius: var(--rounded-lg);
  overflow-x: auto;
  font-family: monospace;
  font-size: 14px;
  margin-bottom: var(--spacing-lg);
  border: 1px solid var(--color-hairline);
}

/* =========================================
   Structural Classes
   ========================================= */
.section-light { 
  background-color: var(--color-canvas); 
  padding: var(--spacing-section) var(--spacing-lg); 
}

.container { 
  max-width: 980px; 
  margin: 0 auto; 
}

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

/* =========================================
   Cards
   ========================================= */
.card {
  background-color: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-radius: var(--rounded-lg);
  padding: var(--spacing-lg);
  text-decoration: none;
  color: inherit;
  display: block;
  transition: transform 0.2s ease;
}

.card:hover { 
  transform: scale(0.98); 
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.card-title { 
  font-weight: 600; 
  font-size: 21px; 
  margin-bottom: 8px; 
}