/* ===== CSS RESET & BASE STYLES ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ===== CSS VARIABLES FOR THEMING ===== */
:root {
  /* Color Palette - Modern Technical Theme */
  --color-bg-primary: #0a0e27;
  --color-bg-secondary: #151932;
  --color-bg-tertiary: #1e2139;
  --color-bg-code: #1a1d35;
  --color-bg-code-inline: #2a2d4a;
  
  --color-text-primary: #e4e7f1;
  --color-text-secondary: #a8b2d1;
  --color-text-muted: #64748b;
  --color-text-code: #64d9ff;
  
  --color-accent-primary: #00d4ff;
  --color-accent-secondary: #7c3aed;
  --color-accent-tertiary: #10b981;
  --color-accent-warning: #f59e0b;
  --color-accent-error: #ef4444;
  
  --color-border: #2a3142;
  --color-border-light: #374151;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', 'Fira Mono', 'Roboto Mono', 'Courier New', monospace;
  
  /* Spacing */
  --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: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.2), 0 6px 10px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 20px rgba(0, 212, 255, 0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

/* ===== BODY & CONTAINER ===== */
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-primary);
  background: linear-gradient(135deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 20% 50%, rgba(0, 212, 255, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(124, 58, 237, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 40% 20%, rgba(16, 185, 129, 0.05) 0%, transparent 50%);
  pointer-events: none;
  z-index: 1;
}

.container {
  position: relative;
  z-index: 2;
  max-width: 900px;
  margin: 0 auto;
  padding: var(--spacing-2xl) var(--spacing-xl);
}

/* ===== TABLE OF CONTENTS ===== */
.toc {
  background: linear-gradient(135deg, var(--color-bg-tertiary), var(--color-bg-secondary));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-2xl);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  position: sticky;
  top: 20px;
  z-index: 10;
}

.toc h3 {
  color: var(--color-accent-primary);
  margin-bottom: var(--spacing-lg);
  font-size: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.toc h3::before {
  content: '📚';
  font-size: 1.5rem;
}

.toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.toc li {
  margin-bottom: var(--spacing-sm);
  padding-left: var(--spacing-lg);
  position: relative;
}

.toc li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--color-accent-primary);
  font-weight: bold;
}

.toc a {
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: all var(--transition-base);
  display: inline-block;
  padding: var(--spacing-xs) 0;
}

.toc a:hover {
  color: var(--color-accent-primary);
  transform: translateX(5px);
  text-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-lg);
  color: var(--color-text-primary);
  position: relative;
  scroll-margin-top: 100px;
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(135deg, var(--color-accent-primary) 0%, var(--color-accent-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

h2 {
  font-size: 2rem;
  color: var(--color-accent-primary);
  border-bottom: 2px solid var(--color-border);
  padding-bottom: var(--spacing-sm);
  margin-top: var(--spacing-3xl);
}

h2:first-child {
  margin-top: 0;
}

h3 {
  font-size: 1.5rem;
  color: var(--color-text-primary);
}

h4 {
  font-size: 1.25rem;
  color: var(--color-accent-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: var(--spacing-xl);
}

h4::before {
  content: '▸ ';
  color: var(--color-accent-primary);
  font-weight: 900;
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
  font-size: 1.05rem;
}

/* ===== LINKS ===== */
a {
  color: var(--color-accent-primary);
  text-decoration: none;
  position: relative;
  transition: color var(--transition-base);
  font-weight: 500;
}

a:hover {
  color: var(--color-accent-secondary);
  text-shadow: 0 0 20px rgba(0, 212, 255, 0.5);
}

a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-accent-primary), var(--color-accent-secondary));
  transition: width var(--transition-base);
}

a:hover::after {
  width: 100%;
}

/* ===== LISTS ===== */
ul, ol {
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-xl);
}

li {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
  position: relative;
}

ul li::marker {
  color: var(--color-accent-primary);
}

li::before {
  content: '';
  position: absolute;
  left: -25px;
  top: 12px;
  width: 6px;
  height: 6px;
  background: var(--color-accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
}

/* ===== HORIZONTAL RULES ===== */
hr {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, 
    transparent, 
    var(--color-accent-primary) 20%, 
    var(--color-accent-secondary) 50%, 
    var(--color-accent-primary) 80%, 
    transparent);
  margin: var(--spacing-2xl) 0;
  position: relative;
  overflow: visible;
}

hr::before {
  content: '◆';
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: var(--color-bg-secondary);
  color: var(--color-accent-primary);
  padding: 0 var(--spacing-md);
  font-size: 12px;
}

/* ===== CODE BLOCKS ===== */
pre {
  background: var(--color-bg-code);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  overflow-x: auto;
  position: relative;
  box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

pre[data-language]::before {
  content: attr(data-language);
  position: absolute;
  top: 0;
  right: 0;
  background: var(--color-accent-primary);
  color: var(--color-bg-primary);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: 0 var(--radius-md) 0 var(--radius-md);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--color-text-code);
  tab-size: 2;
}

/* Inline code */
p code, li code {
  background: var(--color-bg-code-inline);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--color-accent-tertiary);
  border: 1px solid var(--color-border);
  white-space: nowrap;
}

/* Language-specific code block styling */
pre code {
  display: block;
  background: transparent;
  padding: 0;
  border: none;
}

/* Language-specific colors for badges */
pre[data-language="bash"]::before { background: var(--color-accent-tertiary); }
pre[data-language="json"]::before { background: var(--color-accent-warning); }
pre[data-language="js"]::before, pre[data-language="javascript"]::before { background: #f7df1e; color: #000; }
pre[data-language="tsx"]::before, pre[data-language="typescript"]::before { background: #3178c6; }

/* Code syntax highlighting */
code .comment { color: #6b7280; font-style: italic; }
code .keyword { color: #c792ea; font-weight: 600; }
code .string { color: #a5f3fc; }
code .number { color: #f59e0b; }
code .function { color: #67e8f9; }
code .operator { color: #fbbf24; }
code .class-name { color: #fde047; }
code .punctuation { color: #94a3b8; }

/* ===== SPECIAL ELEMENTS ===== */
/* Note callouts */
p:has([NOTE]) {
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.1), rgba(0, 212, 255, 0.1));
  border-left: 4px solid var(--color-accent-secondary);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-md);
  margin: var(--spacing-lg) 0;
  position: relative;
}

p:has([NOTE])::before {
  content: '📝 NOTE';
  position: absolute;
  top: -10px;
  left: 20px;
  background: var(--color-bg-secondary);
  color: var(--color-accent-secondary);
  padding: 0 var(--spacing-sm);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 1px;
}

/* ===== SCROLLBAR STYLING ===== */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--color-accent-primary), var(--color-accent-secondary));
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, var(--color-accent-secondary), var(--color-accent-primary));
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
  .container {
    padding: var(--spacing-lg) var(--spacing-md);
  }
  
  .toc {
    position: relative;
    top: 0;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  h4 { font-size: 1.1rem; }
  
  pre {
    padding: var(--spacing-md);
    font-size: 0.85rem;
  }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.container > * {
  animation: fadeIn 0.6s ease-out;
}

/* ===== PRINT STYLES ===== */
@media print {
  body {
    background: white;
    color: black;
  }
  
  .toc {
    display: none;
  }
  
  pre {
    background: #f5f5f5;
    border: 1px solid #ddd;
  }
  
  a {
    color: #0066cc;
  }
}