/**
 * Placement Papers Website - Main Stylesheet
 * Production-ready CSS with dark mode, responsive design, and print styles
 */

/* ============================================
   CSS RESET & NORMALIZE
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

input, button, textarea, select {
  font: inherit;
}

p, h1, h2, h3, h4, h5, h6 {
  overflow-wrap: break-word;
}

/* ============================================
   CSS CUSTOM PROPERTIES (VARIABLES)
   ============================================ */
:root {
  /* Colors - Light Mode */
  --color-primary: #1a237e;
  --color-primary-light: #3949ab;
  --color-primary-dark: #0d1642;
  --color-accent: #ff6f00;
  --color-accent-light: #ff9800;
  --color-success: #2e7d32;
  --color-success-light: #4caf50;
  --color-warning: #ed6c02;
  --color-error: #d32f2f;
  --color-info: #0288d1;
  
  /* Background Colors */
  --color-bg: #f5f5f5;
  --color-bg-elevated: #ffffff;
  --color-bg-card: #ffffff;
  --color-bg-code: #1e1e1e;
  --color-bg-sidebar: #fafafa;
  
  /* Text Colors */
  --color-text: #212121;
  --color-text-secondary: #757575;
  --color-text-muted: #9e9e9e;
  --color-text-inverse: #ffffff;
  --color-link: var(--color-primary);
  --color-link-hover: var(--color-accent);
  
  /* Border Colors */
  --color-border: #e0e0e0;
  --color-border-light: #f0f0f0;
  --color-border-dark: #bdbdbd;
  
  /* Spacing Scale */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  
  /* Typography Scale */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;
  --text-4xl: 2.5rem;
  
  /* Font Stacks */
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-code: 'Fira Code', 'Consolas', 'Monaco', 'Courier New', monospace;
  
  /* Layout */
  --container-max-width: 1200px;
  --header-height: 64px;
  --sidebar-width: 280px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;
  
  /* Z-Index Scale */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
}

/* ============================================
   DARK MODE
   ============================================ */
[data-theme="dark"] {
  /* Background Colors */
  --color-bg: #121212;
  --color-bg-elevated: #1e1e1e;
  --color-bg-card: #1e1e1e;
  --color-bg-code: #0d0d0d;
  --color-bg-sidebar: #1a1a1a;
  
  /* Text Colors */
  --color-text: #e0e0e0;
  --color-text-secondary: #b0b0b0;
  --color-text-muted: #808080;
  --color-link: #7986cb;
  --color-link-hover: #ffab40;
  
  /* Border Colors */
  --color-border: #333333;
  --color-border-light: #2a2a2a;
  --color-border-dark: #444444;
  
  /* Shadows (subtler in dark mode) */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.5);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.5);
}

/* ============================================
   LAYOUT - CONTAINER & GRID
   ============================================ */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.main-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
  min-height: calc(100vh - var(--header-height));
  padding-top: var(--header-height);
}

/* Content + Sidebar Layout */
.has-sidebar .main-layout {
  grid-template-columns: 1fr;
}

.main-content {
  min-width: 0;
  padding: var(--space-xl) 0;
}

.sidebar {
  display: none;
}

/* ============================================
   RESPONSIVE BREAKPOINTS
   ============================================ */
/* Tablet (768px+) */
@media (min-width: 768px) {
  :root {
    --text-3xl: 2.25rem;
    --text-4xl: 3rem;
  }
  
  .container {
    padding: 0 var(--space-xl);
  }
}

/* Desktop (1024px+) */
@media (min-width: 1024px) {
  .has-sidebar .main-layout {
    grid-template-columns: 1fr var(--sidebar-width);
  }
  
  .sidebar {
    display: block;
    position: sticky;
    top: calc(var(--header-height) + var(--space-lg));
    height: calc(100vh - var(--header-height) - var(--space-2xl));
    overflow-y: auto;
    padding-right: var(--space-md);
  }
  
  .sidebar::-webkit-scrollbar {
    width: 6px;
  }
  
  .sidebar::-webkit-scrollbar-track {
    background: transparent;
  }
  
  .sidebar::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: var(--radius-full);
  }
}

/* Large Desktop (1200px+) */
@media (min-width: 1200px) {
  .has-sidebar .main-layout {
    grid-template-columns: 1fr 320px;
  }
}

/* ============================================
   HEADER
   ============================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(245, 245, 245, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: var(--z-fixed);
  transition: background var(--transition-base), border-color var(--transition-base);
}

[data-theme="dark"] .site-header {
  background: rgba(18, 18, 18, 0.9);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: var(--text-xl);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
}

/* Navigation */
.main-nav {
  display: none;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: var(--space-xs);
}

.nav-link {
  display: block;
  padding: var(--space-sm) var(--space-md);
  color: var(--color-text-secondary);
  text-decoration: none;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background var(--transition-fast);
}

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

[data-theme="dark"] .nav-link:hover,
[data-theme="dark"] .nav-link.active {
  background: var(--color-bg-elevated);
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* Mobile Menu Toggle */
.menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  gap: 5px;
  padding: 0;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform var(--transition-base), opacity var(--transition-base);
  border-radius: 2px;
}

.menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Theme Toggle */
.theme-toggle {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text);
  border-radius: var(--radius-full);
  transition: background var(--transition-fast);
}

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

.theme-toggle .sun-icon,
.theme-toggle .moon-icon {
  width: 20px;
  height: 20px;
}

.theme-toggle .sun-icon {
  display: none;
}

.theme-toggle .moon-icon {
  display: block;
}

[data-theme="dark"] .theme-toggle .sun-icon {
  display: block;
}

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

/* Mobile Navigation Drawer */
.mobile-nav {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  transform: translateX(100%);
  transition: transform var(--transition-base);
  z-index: var(--z-fixed);
  padding: var(--space-lg);
  overflow-y: auto;
}

.mobile-nav.active {
  transform: translateX(0);
}

.mobile-nav .nav-list {
  flex-direction: column;
  gap: var(--space-sm);
}

.mobile-nav .nav-link {
  padding: var(--space-md);
  font-size: var(--text-lg);
}

/* Desktop Header */
@media (min-width: 768px) {
  .menu-toggle {
    display: none;
  }
  
  .main-nav {
    display: block;
  }
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-text-inverse);
  padding: var(--space-3xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  font-size: var(--text-3xl);
  font-weight: 800;
  margin-bottom: var(--space-md);
  line-height: 1.2;
}

.hero p {
  font-size: var(--text-lg);
  opacity: 0.9;
  margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
  .hero {
    padding: var(--space-3xl) 0 calc(var(--space-3xl) * 1.5);
  }
  
  .hero h1 {
    font-size: var(--text-4xl);
  }
}

/* ============================================
   SEARCH
   ============================================ */
.search-container {
  position: relative;
  max-width: 600px;
  margin: 0 auto;
}

.search-input {
  width: 100%;
  padding: var(--space-md) var(--space-md) var(--space-md) 3rem;
  font-size: var(--text-lg);
  border: 2px solid transparent;
  border-radius: var(--radius-xl);
  background: rgba(255, 255, 255, 0.95);
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 4px rgba(255, 111, 0, 0.2);
}

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

/* Search Results */
.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  margin-top: var(--space-sm);
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  max-height: 400px;
  overflow-y: auto;
  z-index: var(--z-dropdown);
  display: none;
}

.search-results.active {
  display: block;
}

.search-result-item {
  display: block;
  padding: var(--space-md);
  border-bottom: 1px solid var(--color-border);
  text-decoration: none;
  color: var(--color-text);
  transition: background var(--transition-fast);
}

.search-result-item:last-child {
  border-bottom: none;
}

.search-result-item:hover,
.search-result-item:focus {
  background: var(--color-bg-sidebar);
}

.search-result-item mark {
  background: rgba(255, 111, 0, 0.2);
  color: var(--color-text);
  padding: 0 2px;
  border-radius: 2px;
}

.search-result-title {
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-primary);
}

.search-result-category {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.search-result-snippet {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
}

.search-no-results {
  padding: var(--space-xl);
  text-align: center;
  color: var(--color-text-secondary);
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.card-link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.card-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--color-bg-sidebar);
}

.card-body {
  padding: var(--space-lg);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.card-title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  line-height: 1.4;
  color: var(--color-text);
}

.card:hover .card-title {
  color: var(--color-primary);
}

.card-text {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: 1.6;
}

/* Article Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

@media (min-width: 640px) {
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .cards-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Category Badge */
.category-badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-primary);
  color: white;
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-radius: var(--radius-sm);
}

.category-badge.accent {
  background: var(--color-accent);
}

.category-badge.success {
  background: var(--color-success);
}

/* Difficulty Tag */
.difficulty-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px var(--space-sm);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 1px solid currentColor;
}

.difficulty-tag.easy {
  color: var(--color-success);
  background: rgba(46, 125, 50, 0.1);
}

.difficulty-tag.medium {
  color: var(--color-warning);
  background: rgba(237, 108, 2, 0.1);
}

.difficulty-tag.hard {
  color: var(--color-error);
  background: rgba(211, 47, 47, 0.1);
}

/* ============================================
   TABLES
   ============================================ */
.table-container {
  overflow-x: auto;
  margin: var(--space-lg) 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

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

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

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

tbody tr:hover {
  background: var(--color-bg-sidebar);
}

/* Zebra Striping */
tbody tr:nth-child(even) {
  background: rgba(0, 0, 0, 0.02);
}

[data-theme="dark"] tbody tr:nth-child(even) {
  background: rgba(255, 255, 255, 0.02);
}

/* Table Caption */
table caption {
  padding: var(--space-md);
  font-weight: 600;
  text-align: left;
  caption-side: top;
  background: var(--color-bg-sidebar);
  border-bottom: 1px solid var(--color-border);
}

/* Responsive Table */
@media (max-width: 640px) {
  .table-container {
    margin: var(--space-md) calc(-1 * var(--space-md));
    border-radius: 0;
    border-left: none;
    border-right: none;
  }
}

/* ============================================
   CODE BLOCKS
   ============================================ */
pre, code {
  font-family: var(--font-code);
  font-size: 0.9em;
}

code {
  background: var(--color-bg-sidebar);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  color: var(--color-accent);
}

pre {
  background: var(--color-bg-code);
  color: #d4d4d4;
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: var(--space-lg) 0;
  position: relative;
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
  font-size: var(--text-sm);
  line-height: 1.6;
}

/* Code Block Header */
.code-block {
  position: relative;
  margin: var(--space-lg) 0;
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  background: #2d2d2d;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  border-bottom: 1px solid #3d3d3d;
}

.code-language {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: #808080;
  font-weight: 600;
}

.code-block pre {
  margin: 0;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* Copy Button */
.copy-button {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  background: #3d3d3d;
  border: none;
  color: #b0b0b0;
  font-size: var(--text-xs);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.copy-button:hover {
  background: #4d4d4d;
  color: #fff;
}

.copy-button.copied {
  color: var(--color-success);
}

/* Syntax Highlighting Colors */
.hljs-keyword,
.token.keyword { color: #569cd6; }

.hljs-string,
.token.string { color: #ce9178; }

.hljs-number,
.token.number { color: #b5cea8; }

.hljs-comment,
.token.comment { color: #6a9955; font-style: italic; }

.hljs-function,
.token.function { color: #dcdcaa; }

.hljs-class,
.token.class-name { color: #4ec9b0; }

.hljs-operator,
.token.operator { color: #d4d4d4; }

.hljs-punctuation,
.token.punctuation { color: #d4d4d4; }

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

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

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

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

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

/* Article Content Typography */
.article-content {
  font-size: 18px;
  line-height: 1.8;
}

.article-content h2 {
  margin-top: var(--space-2xl);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-border);
}

.article-content h3 {
  margin-top: var(--space-xl);
}

.article-content ul,
.article-content ol {
  margin-bottom: var(--space-lg);
  padding-left: var(--space-xl);
}

.article-content li {
  margin-bottom: var(--space-sm);
}

.article-content blockquote {
  margin: var(--space-xl) 0;
  padding: var(--space-md) var(--space-lg);
  border-left: 4px solid var(--color-accent);
  background: var(--color-bg-sidebar);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
}

.article-content img {
  border-radius: var(--radius-md);
  margin: var(--space-xl) 0;
}

/* ============================================
   FAQ ACCORDION
   ============================================ */
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  background: var(--color-bg-card);
  border: none;
  cursor: pointer;
  font-size: var(--text-base);
  font-weight: 600;
  text-align: left;
  color: var(--color-text);
  transition: background var(--transition-fast);
}

.faq-question:hover {
  background: var(--color-bg-sidebar);
}

.faq-icon {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-base);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), padding var(--transition-slow);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 var(--space-lg) var(--space-lg);
}

.faq-answer p:last-child {
  margin-bottom: 0;
}

/* ============================================
   BREADCRUMBS
   ============================================ */
.breadcrumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-xs);
  padding: var(--space-md) 0;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.breadcrumbs a {
  color: var(--color-text-secondary);
}

.breadcrumbs a:hover {
  color: var(--color-link);
}

.breadcrumbs-separator {
  color: var(--color-text-muted);
}

.breadcrumbs-current {
  color: var(--color-text);
  font-weight: 500;
}

/* ============================================
   SHARE BUTTONS
   ============================================ */
.share-section {
  margin: var(--space-2xl) 0;
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.share-title {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.share-buttons {
  display: flex;
  gap: var(--space-sm);
}

.share-button {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--color-bg-sidebar);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: transform var(--transition-fast), background var(--transition-fast), color var(--transition-fast);
}

.share-button:hover {
  transform: translateY(-2px);
  color: white;
  text-decoration: none;
}

.share-button.whatsapp:hover { background: #25d366; }
.share-button.telegram:hover { background: #0088cc; }
.share-button.twitter:hover { background: #000000; }
.share-button.copy:hover { background: var(--color-primary); }

[data-theme="dark"] .share-button.twitter:hover { background: #ffffff; color: #000; }

/* ============================================
   TABLE OF CONTENTS (TOC)
   ============================================ */
.toc {
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
}

.toc-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.toc-title {
  font-size: var(--text-base);
  font-weight: 700;
  margin: 0;
}

.toc-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

@media (min-width: 1024px) {
  .toc-toggle {
    display: none;
  }
}

.toc-toggle:hover {
  background: var(--color-bg-sidebar);
}

.toc-list {
  list-style: none;
}

.toc-list.collapsed {
  display: none;
}

@media (min-width: 1024px) {
  .toc-list.collapsed {
    display: block;
  }
}

.toc-item {
  margin-bottom: var(--space-xs);
}

.toc-link {
  display: block;
  padding: var(--space-xs) var(--space-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background var(--transition-fast);
  border-left: 2px solid transparent;
}

.toc-link:hover {
  color: var(--color-link);
  background: var(--color-bg-sidebar);
}

.toc-link.active {
  color: var(--color-primary);
  background: rgba(26, 35, 126, 0.08);
  border-left-color: var(--color-primary);
  font-weight: 600;
}

[data-theme="dark"] .toc-link.active {
  background: rgba(121, 134, 203, 0.15);
  color: var(--color-link);
}

.toc-sublist {
  list-style: none;
  padding-left: var(--space-md);
}

.toc-sublist .toc-link {
  font-size: var(--text-xs);
}

/* ============================================
   STATS COUNTER
   ============================================ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

@media (min-width: 640px) {
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stat-item {
  text-align: center;
  padding: var(--space-lg);
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.stat-number {
  font-size: var(--text-3xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ============================================
   PAGINATION
   ============================================ */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-xs);
  margin: var(--space-2xl) 0;
  flex-wrap: wrap;
}

.pagination-link,
.pagination-current {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  padding: 0 var(--space-sm);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
}

.pagination-link {
  color: var(--color-text-secondary);
  text-decoration: none;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast);
}

.pagination-link:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  text-decoration: none;
}

.pagination-current {
  background: var(--color-primary);
  color: white;
  font-weight: 600;
}

.pagination-ellipsis {
  color: var(--color-text-muted);
  padding: 0 var(--space-sm);
}

/* ============================================
   BACK TO TOP BUTTON
   ============================================ */
.back-to-top {
  position: fixed;
  bottom: var(--space-lg);
  right: var(--space-lg);
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--transition-base), visibility var(--transition-base), transform var(--transition-base), background var(--transition-fast);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-fixed);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-primary-light);
  transform: translateY(-2px);
}

/* ============================================
   READING PROGRESS BAR
   ============================================ */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  z-index: calc(var(--z-fixed) + 1);
  width: 0%;
  transition: width 0.1s linear;
}

/* ============================================
   PRINT BUTTON
   ============================================ */
.print-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-bg-sidebar);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.print-button:hover {
  background: var(--color-bg-card);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ============================================
   PAGE HEADER
   ============================================ */
.page-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
}

.page-title {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-sm);
}

.page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

/* ============================================
   SECTIONS
   ============================================ */
.section {
  padding: var(--space-2xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-title {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-sm);
}

.section-subtitle {
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--text-base);
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
  border: none;
}

.btn:hover {
  transform: translateY(-1px);
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: 0 4px 6px rgba(26, 35, 126, 0.2);
}

.btn-primary:hover {
  background: var(--color-primary-light);
  box-shadow: 0 6px 12px rgba(26, 35, 126, 0.3);
  color: white;
}

.btn-accent {
  background: var(--color-accent);
  color: white;
  box-shadow: 0 4px 6px rgba(255, 111, 0, 0.2);
}

.btn-accent:hover {
  background: var(--color-accent-light);
  box-shadow: 0 6px 12px rgba(255, 111, 0, 0.3);
  color: white;
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: white;
}

/* ============================================
   FOOTER
   ============================================ */
.site-footer {
  background: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.8);
  padding: var(--space-3xl) 0 var(--space-xl);
  margin-top: var(--space-3xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-2xl);
}

@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 2fr repeat(3, 1fr);
  }
}

.footer-brand .logo {
  color: white;
  margin-bottom: var(--space-md);
}

.footer-description {
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--text-sm);
  max-width: 300px;
}

.footer-title {
  color: white;
  font-size: var(--text-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--space-md);
}

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

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

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: white;
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  text-align: center;
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.copyright {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.5);
}

/* ============================================
   ANIMATIONS & UTILITIES
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn 0.5s ease forwards;
}

/* Scroll-triggered fade in */
.fade-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Screen reader only */
.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;
}

/* Focus visible */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
  /* Hide non-essential elements */
  .site-header,
  .site-footer,
  .sidebar,
  .share-section,
  .back-to-top,
  .reading-progress,
  .print-button,
  .mobile-nav,
  .menu-toggle,
  .theme-toggle,
  .toc-toggle,
  .copy-button,
  .hero {
    display: none !important;
  }
  
  /* Reset colors for print */
  :root {
    --color-text: #000000;
    --color-bg: #ffffff;
    --color-bg-card: #ffffff;
    --color-link: #0000ee;
  }
  
  body {
    background: white;
    color: black;
    font-size: 12pt;
    line-height: 1.5;
  }
  
  .main-layout {
    display: block;
    padding-top: 0;
  }
  
  .main-content {
    padding: 0;
    max-width: 100%;
  }
  
  /* Ensure links are visible */
  a {
    color: #0000ee;
    text-decoration: underline;
  }
  
  /* Show URLs after links */
  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 90%;
    color: #666;
    word-break: break-all;
  }
  
  /* Don't show URL for internal anchors */
  a[href^="#"]::after,
  a[href^="javascript:"]::after {
    content: "";
  }
  
  /* Page breaks */
  h1, h2, h3 {
    page-break-after: avoid;
  }
  
  pre, blockquote, table {
    page-break-inside: avoid;
  }
  
  /* Code blocks */
  pre {
    background: #f5f5f5 !important;
    color: #000 !important;
    border: 1px solid #ddd;
    white-space: pre-wrap;
    word-wrap: break-word;
  }
  
  code {
    background: #f5f5f5 !important;
    color: #000 !important;
  }
  
  /* Cards */
  .card {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }
  
  .card:hover {
    transform: none;
  }
  
  /* Tables */
  table {
    border: 1px solid #ddd;
  }
  
  th, td {
    border: 1px solid #ddd;
  }
  
  /* Article content */
  .article-content {
    font-size: 12pt;
  }
}