/* ==========================================
   CSS Variables & Root Styles
   ========================================== */
:root {
  /* Colors - Light Theme */
  --color-primary: #3b82f6;
  --color-primary-hover: #2563eb;
  --color-secondary: #8b5cf6;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;

  --color-bg: #ffffff;
  --color-bg-secondary: #f9fafb;
  --color-bg-tertiary: #f3f4f6;
  --color-surface: #ffffff;
  --color-surface-hover: #f9fafb;

  --color-text: #111827;
  --color-text-secondary: #6b7280;
  --color-text-tertiary: #9ca3af;

  --color-border: #e5e7eb;
  --color-border-hover: #d1d5db;

  --color-code-bg: #1f2937;
  --color-code-text: #f9fafb;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --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);

  /* 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: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Typography */
  --font-family-base: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, sans-serif;
  --font-family-mono: "JetBrains Mono", "Fira Code", "Consolas", monospace;

  --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;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;

  /* Layout */
  --header-height: 70px;
  --sidebar-width: 280px;
  --toc-width: 240px;
  --content-max-width: 1400px;
}

/* Dark Theme */
[data-theme="dark"] {
  --color-bg: #0f172a;
  --color-bg-secondary: #1e293b;
  --color-bg-tertiary: #334155;
  --color-surface: #1e293b;
  --color-surface-hover: #334155;

  --color-text: #f1f5f9;
  --color-text-secondary: #cbd5e1;
  --color-text-tertiary: #94a3b8;

  --color-border: #334155;
  --color-border-hover: #475569;

  --color-code-bg: #0f172a;
  --color-code-text: #f1f5f9;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 2rem);
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition-base),
    color var(--transition-base);
  overflow-x: hidden;
}

/* ==========================================
   Typography
   ========================================== */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--spacing-lg);
  color: var(--color-text);
}


h1 {
  font-size: clamp(2rem, 4vw, 2.25rem);
}
h2 {
  font-size: clamp(1.5rem, 3vw, 1.875rem);
}
h3 {
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
}
h4 {
  font-size: clamp(1.125rem, 2vw, 1.25rem);
}
h5 {
  font-size: clamp(1rem, 1.5vw, 1.125rem);
}
h6 {
  font-size: var(--font-size-base);
}

  transition: color var(--transition-fast);
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
  outline: none;
}
a:hover,
}
  color: var(--color-primary-hover);
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

code {
  font-family: var(--font-family-mono);
  font-size: 0.9em;
  background-color: var(--color-bg-tertiary);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  color: var(--color-text);
}

pre {
  background-color: var(--color-code-bg);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  overflow-x: auto;
  margin-bottom: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

pre code {
  background: none;
  padding: 0;
  color: var(--color-code-text);
  font-size: var(--font-size-sm);
}

blockquote {
  border-left: 4px solid var(--color-primary);
  padding-left: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  font-style: italic;
  color: var(--color-text-secondary);
}

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

.gradient-text {
  background: linear-gradient(
    135deg,
    var(--color-primary),
    var(--color-secondary)
  );
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ==========================================
   Loading Overlay
   ========================================== */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--color-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  transition: opacity var(--transition-base);
}

.loading-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.loader {
  width: 50px;
  height: 50px;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.loading-overlay p {
  margin-top: var(--spacing-lg);
  color: var(--color-text-secondary);
}

/* ==========================================
   Header
   ========================================== */
.header {
  position: sticky;
  top: 0;
  height: var(--header-height);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(10px);
  background-color: rgba(255, 255, 255, 0.8);
  z-index: 1000;
  transition: all var(--transition-base);
}

[data-theme="dark"] .header {
  background-color: rgba(30, 41, 59, 0.8);
}

.header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: var(--spacing-lg);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text);
}

.logo-icon {
  width: 32px;
  height: 32px;
  color: var(--color-primary);
}

.nav-menu {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

.nav-link {
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-secondary);
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
  background-color: var(--color-bg-tertiary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.theme-toggle {
  width: 40px;
  height: 40px;
  border: none;
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--color-border);
}

.theme-icon {
  width: 20px;
  height: 20px;
  color: var(--color-text);
}

.sun-icon {
  display: block;
}
.moon-icon {
  display: none;
}

[data-theme="dark"] .sun-icon {
  display: none;
}
[data-theme="dark"] .moon-icon {
  display: block;
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
}

.mobile-menu-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

/* ==========================================
   Hero Section
   ========================================== */
.hero {
  position: relative;
  padding: var(--spacing-3xl) 0;
  overflow: hidden;
  background: linear-gradient(
    135deg,
    var(--color-bg) 0%,
    var(--color-bg-secondary) 100%
  );
}

.hero-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(
      circle at 20% 50%,
      rgba(59, 130, 246, 0.1) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 80% 80%,
      rgba(139, 92, 246, 0.1) 0%,
      transparent 50%
    );
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 500;
  margin-bottom: var(--spacing-xl);
  box-shadow: var(--shadow-sm);
}

.hero-title {
  font-size: var(--font-size-5xl);
  margin-bottom: var(--spacing-lg);
  line-height: 1.2;
}

.hero-description {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2xl);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  margin-bottom: var(--spacing-3xl);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-xl);
  margin-top: var(--spacing-3xl);
  padding-top: var(--spacing-2xl);
  border-top: 1px solid var(--color-border);
}

.stat {
  text-align: center;
}

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

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  font-weight: 500;
}

/* ==========================================
   Buttons
   ========================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-base);
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  outline: none;
}
.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-lg);
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: var(--shadow);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-border-hover);
}

/* ==========================================
   Main Content Layout
   ========================================== */
.main-content {
  padding: var(--spacing-3xl) 0;
}

.content-wrapper {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr var(--toc-width);
  gap: var(--spacing-2xl);
  align-items: start;
}

/* ==========================================
   Sidebar
   ========================================== */
.sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--spacing-lg));
  height: calc(100vh - var(--header-height) - var(--spacing-2xl));
  overflow-y: auto;
}

.sidebar-sticky {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
}

.sidebar-search {
  position: relative;
  margin-bottom: var(--spacing-lg);
}

.search-input {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  padding-left: calc(var(--spacing-md) + 24px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-icon {
  position: absolute;
  left: var(--spacing-sm);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-tertiary);
  pointer-events: none;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.sidebar-nav a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
  background: var(--color-bg-tertiary);
  color: var(--color-primary);
}

/* ==========================================
   Content
   ========================================== */
.content {
  min-width: 0;
}

.content-section {
  margin-bottom: var(--spacing-3xl);
}

.content-section h2 {
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-md);
  border-bottom: 2px solid var(--color-border);
}

.loading-placeholder {
  padding: var(--spacing-2xl);
  text-align: center;
  color: var(--color-text-tertiary);
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--spacing-lg) 0;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
}

thead {
  background: var(--color-bg-tertiary);
}

th,
td {
  padding: var(--spacing-md);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

th {
  font-weight: 600;
  color: var(--color-text);
}

td {
  color: var(--color-text-secondary);
}

tr:last-child td {
  border-bottom: none;
}

/* Lists */
ul,
ol {
  margin-left: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

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

/* ==========================================
   Table of Contents
   ========================================== */
.toc {
  position: sticky;
  top: calc(var(--header-height) + var(--spacing-lg));
  height: calc(100vh - var(--header-height) - var(--spacing-2xl));
  overflow-y: auto;
}

.toc-sticky {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
}

.toc-title {
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
  margin-bottom: var(--spacing-md);
}

.toc-nav {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.toc-nav a {
  display: block;
  padding: var(--spacing-xs) var(--spacing-sm);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
}

.toc-nav a:hover,
.toc-nav a.active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
}

/* ==========================================
   Footer
   ========================================== */
.footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
  margin-top: var(--spacing-3xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.footer-section h4 {
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-base);
}

.footer-section p {
  font-size: var(--font-size-sm);
}

.footer-badges {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

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

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

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

.footer-bottom {
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.last-updated {
  margin-top: var(--spacing-sm);
}

/* ==========================================
   Scroll to Top Button
   ========================================== */
.scroll-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 999;
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 1200px) {
  .content-wrapper {
    grid-template-columns: var(--sidebar-width) 1fr;
  }

  .toc {
    display: none;
  }
}

@media (max-width: 968px) {
  :root {
    --sidebar-width: 250px;
  }

  .nav-menu {
    display: none;
  }

  .mobile-menu-toggle {
    display: flex;
  }

  .hero-title {
    font-size: var(--font-size-3xl);
  }

  .hero-description {
    font-size: var(--font-size-base);
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .content-wrapper {
    grid-template-columns: 1fr;
  }

  .sidebar {
    display: none;
  }

  .hero-actions {
    flex-direction: column;
  }

  .footer-content {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .header-content {
    gap: var(--spacing-sm);
  }

  .hero {
    padding: var(--spacing-2xl) 0;
  }

  .hero-title {
    font-size: var(--font-size-2xl);
  }

  .hero-stats {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }
}

/* ==========================================
   Utilities
   ========================================== */
.text-center {
  text-align: center;
}
.text-left {
  text-align: left;
}
.text-right {
  text-align: right;
}

.hidden {
  display: none !important;
}
.visible {
  display: block !important;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-border-hover);
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f172a;
    --color-bg-secondary: #1e293b;
    --color-bg-tertiary: #334155;
    --color-surface: #1e293b;
    --color-surface-hover: #334155;
    --color-text: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-tertiary: #94a3b8;
    --color-border: #334155;
    --color-border-hover: #475569;
    --color-code-bg: #0f172a;
    --color-code-text: #f1f5f9;
  }
}

/* Selection */
::selection {
  background: rgba(59, 130, 246, 0.2);
  color: var(--color-text);
}

/* Search Highlighting */
mark.search-highlight {
  background-color: rgba(59, 130, 246, 0.3);
  color: var(--color-text);
  padding: 0.1em 0.2em;
  border-radius: var(--radius-sm);
  font-weight: 500;
}

[data-theme="dark"] mark.search-highlight {
  background-color: rgba(59, 130, 246, 0.4);
}

/* Error Message Styling */
.error-message {
  animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}