/* ===================================
   RESET & BASE STYLES
   =================================== */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Colors */
  --primary: #7c3aed;
  --primary-dark: #6d28d9;
  --primary-light: #a78bfa;
  --secondary: #10b981;
  --accent: #f59e0b;
  --danger: #ef4444;
  --warning: #fbbf24;
  
  /* Neutrals */
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Border radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --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);
  
  /* Transitions */
  --transition: all 0.3s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-800);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

ul {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ===================================
   CONTAINER & LAYOUT
   =================================== */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* ===================================
   HEADER & NAVIGATION
   =================================== */

#header {
  position: sticky;
  top: 0;
  width: 100%;
  background-color: var(--white);
  border-bottom: 1px solid var(--gray-200);
  z-index: 1000;
  transition: var(--transition);
}

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

.nav-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  min-height: 70px;
}

.brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  cursor: pointer;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 21px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 10;
}

.nav-toggle .hamburger {
  display: block;
  width: 100%;
  height: 3px;
  background-color: var(--gray-800);
  border-radius: 3px;
  transition: var(--transition);
  position: relative;
}

.nav-toggle .hamburger::before,
.nav-toggle .hamburger::after {
  content: '';
  position: absolute;
  width: 100%;
  height: 3px;
  background-color: var(--gray-800);
  border-radius: 3px;
  transition: var(--transition);
}

.nav-toggle .hamburger::before {
  top: -9px;
}

.nav-toggle .hamburger::after {
  top: 9px;
}

.nav-toggle[aria-expanded="true"] .hamburger {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .hamburger::before {
  transform: rotate(45deg);
  top: 0;
}

.nav-toggle[aria-expanded="true"] .hamburger::after {
  transform: rotate(-45deg);
  top: 0;
}

.main-nav ul {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.main-nav a {
  font-weight: 500;
  color: var(--gray-700);
  padding: var(--spacing-xs) 0;
  position: relative;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary);
  transition: width 0.3s ease;
}

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

.main-nav a:hover::after {
  width: 100%;
}

.nav-cta {
  white-space: nowrap;
  background-color: var(--primary);
  color: var(--white) !important;
  padding: var(--spacing-xs) var(--spacing-md) !important;
  border-radius: var(--radius-md);
  font-weight: 600;
}

.nav-cta::after {
  display: none;
}

.nav-cta:hover {
  background-color: var(--primary-dark);
  color: var(--white) !important;
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background-color: var(--white);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .main-nav ul {
    flex-direction: column;
    gap: 0;
    padding: var(--spacing-md);
  }

  .main-nav li {
    width: 100%;
    border-bottom: 1px solid var(--gray-200);
  }

  .main-nav li:last-child {
    border-bottom: none;
  }

  .main-nav a {
    display: block;
    padding: var(--spacing-md);
  }

  .nav-cta {
    white-space: nowrap;
    margin-top: var(--spacing-sm);
    text-align: center;
  }
}

/* ===================================
   HERO SECTION
   =================================== */

.hero {
  padding: var(--spacing-2xl) 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: var(--white);
  text-align: center;
}

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

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  background-color: rgba(255, 255, 255, 0.2);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-xl);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: var(--spacing-md);
  backdrop-filter: blur(10px);
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.125rem;
  opacity: 0.95;
  max-width: 700px;
  margin: 0 auto;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 1.875rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }
}

/* ===================================
   BLOG SECTION
   =================================== */

.blog-section {
  padding: var(--spacing-2xl) 0;
  background-color: var(--gray-50);
}

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

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: var(--spacing-xs);
}

.section-header p {
  font-size: 1.125rem;
  color: var(--gray-600);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-lg);
}

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

/* Blog Cards */
.blog-card {
  background-color: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

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

.blog-image {
  position: relative;
  overflow: hidden;
  height: 220px;
}

.blog-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.blog-card:hover .blog-image img {
  transform: scale(1.05);
}

.blog-category {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  background-color: var(--primary);
  color: var(--white);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-md);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.blog-content {
  padding: var(--spacing-md);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.blog-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 0.875rem;
  color: var(--gray-500);
  margin-bottom: var(--spacing-sm);
  flex-wrap: wrap;
}

.blog-meta svg {
  flex-shrink: 0;
}

.reading-time {
  display: flex;
  align-items: center;
  gap: 4px;
}

.blog-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: var(--spacing-sm);
  line-height: 1.4;
}

.blog-content h3 a {
  color: inherit;
}

.blog-content h3 a:hover {
  color: var(--primary);
}

.blog-content p {
  color: var(--gray-600);
  margin-bottom: var(--spacing-md);
  flex: 1;
}

.read-more {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--primary);
  font-weight: 600;
  font-size: 0.875rem;
  transition: var(--transition);
}

.read-more:hover {
  gap: var(--spacing-sm);
  color: var(--primary-dark);
}

.read-more svg {
  transition: transform 0.3s ease;
}

.read-more:hover svg {
  transform: translateX(4px);
}

/* ===================================
   FULL ARTICLES
   =================================== */

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

.full-article {
  max-width: 800px;
  margin: 0 auto var(--spacing-2xl);
  scroll-margin-top: 100px;
}

.full-article:last-child {
  margin-bottom: 0;
}

.article-header {
  margin-bottom: var(--spacing-lg);
}

.article-header .article-category {
  display: inline-block;
  background-color: var(--primary);
  color: var(--white);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--spacing-md);
}

.article-header h2 {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--gray-900);
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--gray-500);
  flex-wrap: wrap;
}

.article-image {
  margin-bottom: var(--spacing-lg);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.article-image img {
  width: 100%;
  height: auto;
  max-height: 500px;
  object-fit: cover;
}

.article-content {
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--gray-700);
}

.article-content .lead {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--gray-800);
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.article-content h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
}

.article-content h4 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

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

.article-content ul {
  list-style: disc;
  margin-left: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
}

.article-content ul ul {
  margin-top: var(--spacing-xs);
  margin-bottom: var(--spacing-xs);
}

.article-content li {
  margin-bottom: var(--spacing-xs);
  padding-left: var(--spacing-xs);
}

.article-content strong {
  font-weight: 600;
  color: var(--gray-900);
}

/* Article Callout Boxes */
.article-callout {
  background-color: var(--gray-50);
  border-left: 4px solid var(--primary);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin: var(--spacing-lg) 0;
  display: flex;
  gap: var(--spacing-md);
}

.article-callout.warning {
  background-color: #fef3c7;
  border-left-color: var(--warning);
}

.article-callout svg {
  flex-shrink: 0;
  color: var(--primary);
  margin-top: 2px;
}

.article-callout.warning svg {
  color: var(--warning);
}

.article-callout strong {
  display: block;
  margin-bottom: var(--spacing-xs);
  color: var(--gray-900);
}

.article-callout p {
  margin-bottom: 0;
  font-size: 0.9375rem;
}

/* Article CTA */
.article-cta {
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-lg);
  border-top: 2px solid var(--gray-200);
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

@media (max-width: 768px) {
  .article-header h2 {
    font-size: 1.75rem;
  }

  .article-content {
    font-size: 1rem;
  }

  .article-content .lead {
    font-size: 1.125rem;
  }

  .article-content h3 {
    font-size: 1.25rem;
  }

  .article-content h4 {
    font-size: 1.125rem;
  }

  .article-cta {
    flex-direction: column;
  }
}

/* ===================================
   BUTTONS
   =================================== */

.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
  line-height: 1.5;
}

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

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

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

.btn.outline:hover {
  background-color: var(--primary);
  color: var(--white);
  transform: translateY(-2px);
}

/* ===================================
   BLOG CTA SECTION
   =================================== */

.blog-cta {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: var(--white);
  padding: var(--spacing-2xl) 0;
  text-align: center;
}

.cta-content h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

.cta-content p {
  font-size: 1.125rem;
  margin-bottom: var(--spacing-lg);
  opacity: 0.95;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.cta-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.blog-cta .btn.primary {
  background-color: var(--white);
  color: var(--primary);
  border-color: var(--white);
}

.blog-cta .btn.primary:hover {
  background-color: var(--gray-100);
  border-color: var(--gray-100);
  color: var(--primary-dark);
}

.blog-cta .btn.outline {
  background-color: transparent;
  color: var(--white);
  border-color: var(--white);
}

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

@media (max-width: 768px) {
  .cta-content h2 {
    font-size: 1.5rem;
  }

  .cta-buttons {
    flex-direction: column;
  }

  .blog-cta .btn {
    width: 100%;
  }
}

/* ===================================
   FOOTER
   =================================== */

footer {
  background-color: var(--gray-900);
  color: var(--gray-300);
  padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-container {
  max-width: 1200px;
}

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

.footer-col h4 {
  color: var(--white);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-col a {
  color: var(--gray-400);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.footer-col a:hover {
  color: var(--white);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  font-size: 1.25rem;
}

.logo-icon {
  flex-shrink: 0;
}

.footer-col p {
  color: var(--gray-400);
  line-height: 1.6;
}

.footer-bottom {
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--gray-800);
  text-align: center;
  color: var(--gray-500);
  font-size: 0.875rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.footer-social {
  display: flex;
  gap: var(--spacing-md);
}

.footer-social a {
  color: var(--gray-400);
  transition: var(--transition);
}

.footer-social a:hover {
  color: var(--white);
  transform: translateY(-2px);
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ===================================
   UTILITY CLASSES
   =================================== */

.text-center {
  text-align: center;
}

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

.mt-md {
  margin-top: var(--spacing-md);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mb-sm {
  margin-bottom: var(--spacing-sm);
}

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

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

/* ===================================
   ANIMATIONS
   =================================== */

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

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

/* ===================================
   ACCESSIBILITY
   =================================== */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus styles */
a:focus,
button:focus {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* ===================================
   PRINT STYLES
   =================================== */

@media print {
  header,
  footer,
  .blog-cta,
  .article-cta,
  .nav-toggle {
    display: none;
  }

  body {
    font-size: 12pt;
  }

  .article-content {
    max-width: 100%;
  }

  a {
    text-decoration: underline;
  }

  img {
    max-width: 100%;
    page-break-inside: avoid;
  }
}

/* ===================================
   ENHANCED FEATURES - TABLE OF CONTENTS
   =================================== */

.article-toc {
  position: fixed;
  left: 0;
  top: 120px;
  width: 280px;
  max-height: calc(100vh - 200px);
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-md);
  z-index: 900;
  overflow-y: auto;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.toc-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--gray-200);
  color: var(--primary);
}

.toc-header svg {
  flex-shrink: 0;
}

.toc-header h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0;
}

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

.toc-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  color: var(--gray-700);
  transition: var(--transition);
  font-size: 0.875rem;
  border-left: 3px solid transparent;
}

.toc-link:hover {
  background-color: var(--gray-50);
  color: var(--primary);
  border-left-color: var(--primary);
}

.toc-link.active {
  background-color: var(--primary);
  color: var(--white);
  font-weight: 600;
  border-left-color: var(--primary-dark);
}

.toc-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background-color: var(--gray-200);
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}

.toc-link.active .toc-number {
  background-color: var(--white);
  color: var(--primary);
}

.toc-title {
  flex: 1;
  line-height: 1.3;
}

.toc-toggle {
  display: none;
  position: fixed;
  left: var(--spacing-md);
  bottom: var(--spacing-md);
  width: 56px;
  height: 56px;
  background-color: var(--primary);
  color: var(--white);
  border-radius: 50%;
  box-shadow: var(--shadow-xl);
  z-index: 901;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.toc-toggle:hover {
  background-color: var(--primary-dark);
  transform: scale(1.1);
}

.toc-toggle:active {
  transform: scale(0.95);
}

/* TOC Mobile Styles */
@media (max-width: 1200px) {
  .article-toc {
    transform: translateX(-100%);
    opacity: 0;
    left: var(--spacing-md);
    top: 80px;
    width: 260px;
  }

  .article-toc.toc-open {
    transform: translateX(0);
    opacity: 1;
  }

  .toc-toggle {
    display: flex;
  }
}

@media (max-width: 768px) {
  .article-toc {
    width: calc(100% - 2rem);
    max-width: 320px;
  }
}

.articles-wrapper {
  max-width: 800px;
  margin: 0 auto;
}

/* ===================================
   BREADCRUMB NAVIGATION
   =================================== */

.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 0.875rem;
  color: var(--gray-600);
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--primary);
  font-weight: 500;
  transition: var(--transition);
}

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

.breadcrumb svg {
  color: var(--gray-400);
  flex-shrink: 0;
}

.breadcrumb span {
  color: var(--gray-700);
  font-weight: 500;
}

/* ===================================
   ARTICLE NAVIGATION (PREV/NEXT)
   =================================== */

.article-navigation {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-lg);
  border-top: 2px solid var(--gray-200);
}

.article-navigation .article-nav-link {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  padding: var(--spacing-md);
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-lg);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.article-navigation .article-nav-link::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 0;
}

.article-navigation .article-nav-link:hover::before {
  opacity: 1;
}

.article-navigation .article-nav-link:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.article-navigation .article-nav-link > * {
  position: relative;
  z-index: 1;
  transition: color 0.3s ease;
}

.article-navigation .article-nav-link:hover > * {
  color: var(--white) !important;
}

.article-nav-link.prev {
  text-align: left;
}

.article-nav-link.next {
  text-align: right;
  align-items: flex-end;
}

.article-nav-link svg {
  width: 20px;
  height: 20px;
  color: var(--primary);
  transition: var(--transition);
}

.article-nav-link:hover svg {
  color: var(--white);
}

.article-nav-link.prev:hover svg {
  transform: translateX(-4px);
}

.article-nav-link.next:hover svg {
  transform: translateX(4px);
}

.nav-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: var(--gray-500);
}

.nav-title {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--gray-900);
  line-height: 1.4;
}

.article-nav-link:hover .nav-title {
  color: var(--white);
}

/* Single navigation link (first/last article) */
.article-navigation .article-nav-link:only-child {
  grid-column: 1 / -1;
}

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

  .article-nav-link.next,
  .article-nav-link.prev {
    text-align: left;
    align-items: flex-start;
  }
}

/* ===================================
   SCROLL PROGRESS INDICATOR
   =================================== */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: var(--gray-200);
  z-index: 1001;
}

.scroll-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-light) 100%);
  width: 0%;
  transition: width 0.1s ease;
}

/* ===================================
   ARTICLE READING PROGRESS CIRCLE
   =================================== */

.article-progress {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  z-index: 950;
  opacity: 0;
  transform: scale(0.8);
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
}

.article-progress.visible {
  opacity: 1;
  transform: scale(1);
}

.progress-circle {
  position: relative;
  width: 60px;
  height: 60px;
}

.progress-circle svg {
  transform: rotate(-90deg);
}

.progress-circle-bg {
  fill: none;
  stroke: var(--gray-200);
  stroke-width: 4;
}

.progress-circle-fill {
  fill: none;
  stroke: var(--primary);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-dasharray: 175.93; /* 2 * PI * 28 */
  stroke-dashoffset: 175.93;
  transition: stroke-dashoffset 0.3s ease;
}

.progress-percent {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary);
}

@media (max-width: 768px) {
  .article-progress {
    bottom: 80px;
    right: var(--spacing-md);
  }

  .progress-circle {
    width: 50px;
    height: 50px;
  }

  .progress-circle-bg,
  .progress-circle-fill {
    r: 23;
  }

  .progress-circle svg {
    width: 50px;
    height: 50px;
  }
}

/* ===================================
   SHARE & PRINT BUTTONS
   =================================== */

.btn-share {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-md);
  background-color: var(--gray-100);
  color: var(--gray-700);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  transition: var(--transition);
  border: 1px solid var(--gray-300);
  margin-left: auto;
}

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

.article-header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--spacing-md);
}

.article-header > div:first-child {
  flex: 1;
  min-width: 0;
}

/* ===================================
   DARK MODE STYLES
   =================================== */

.dark-mode-toggle {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 50px;
  height: 50px;
  background-color: var(--gray-800);
  color: var(--white);
  border-radius: 50%;
  box-shadow: var(--shadow-xl);
  z-index: 960;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  border: 2px solid var(--gray-700);
}

.dark-mode-toggle:hover {
  background-color: var(--gray-700);
  transform: rotate(180deg) scale(1.1);
}

@media (max-width: 768px) {
  .dark-mode-toggle {
    bottom: 140px;
    right: var(--spacing-md);
    width: 45px;
    height: 45px;
  }
}

/* Dark Mode Color Overrides */
body.dark-mode {
  background-color: var(--gray-900);
  color: var(--gray-100);
}

body.dark-mode #header {
  background-color: var(--gray-800);
  border-bottom-color: var(--gray-700);
}

body.dark-mode .hero {
  background: linear-gradient(135deg, #5b21b6 0%, #4c1d95 100%);
}

body.dark-mode .blog-section {
  background-color: var(--gray-800);
}

body.dark-mode .blog-card {
  background-color: var(--gray-900);
  border: 1px solid var(--gray-700);
}

body.dark-mode .blog-content h3 a {
  color: var(--gray-100);
}

body.dark-mode .blog-content p {
  color: var(--gray-400);
}

body.dark-mode .article-toc {
  background-color: var(--gray-800);
  border: 1px solid var(--gray-700);
}

body.dark-mode .toc-link {
  color: var(--gray-300);
}

body.dark-mode .toc-link:hover {
  background-color: var(--gray-700);
}

body.dark-mode .article-content {
  color: var(--gray-300);
}

body.dark-mode .article-header h2,
body.dark-mode .article-content h3,
body.dark-mode .article-content h4,
body.dark-mode .article-content strong {
  color: var(--gray-100);
}

body.dark-mode .article-callout {
  background-color: var(--gray-800);
  border-left-color: var(--primary-light);
}

body.dark-mode .article-nav-link {
  background-color: var(--gray-800);
  border-color: var(--gray-700);
}

body.dark-mode .breadcrumb a {
  color: var(--primary-light);
}

body.dark-mode .scroll-progress {
  background-color: var(--gray-800);
}

body.dark-mode footer {
  background-color: #000000;
}

/* ===================================
   PRINT MODE
   =================================== */

body.print-mode .blog-section,
body.print-mode .blog-cta,
body.print-mode header,
body.print-mode footer,
body.print-mode .article-toc,
body.print-mode .toc-toggle,
body.print-mode .scroll-progress,
body.print-mode .article-progress,
body.print-mode .dark-mode-toggle,
body.print-mode .btn-share,
body.print-mode .article-navigation {
  display: none !important;
}

body.print-mode .full-article {
  display: block !important;
}

/* ===================================
   ANIMATIONS
   =================================== */

@keyframes slideInFromLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInFromRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

.full-article {
  animation: fadeInUp 0.6s ease-out;
}

.toc-link {
  animation: slideInFromLeft 0.3s ease-out;
}

.article-nav-link {
  animation: fadeInUp 0.5s ease-out;
}

/* Stagger animation for TOC links */
.toc-link:nth-child(1) { animation-delay: 0.05s; }
.toc-link:nth-child(2) { animation-delay: 0.1s; }
.toc-link:nth-child(3) { animation-delay: 0.15s; }
.toc-link:nth-child(4) { animation-delay: 0.2s; }
.toc-link:nth-child(5) { animation-delay: 0.25s; }
.toc-link:nth-child(6) { animation-delay: 0.3s; }

/* ===================================
   RESPONSIVE IMPROVEMENTS
   =================================== */

@media (max-width: 1400px) {
  .article-toc {
    width: 240px;
  }
}

@media (max-width: 768px) {
  .article-header {
    flex-direction: column;
  }

  .btn-share {
    width: 100%;
    justify-content: center;
  }
}

/* Hide blog grid when viewing article (controlled by JS) */
.blog-section.hidden {
  display: none;
}