/* ============================================
   ENHANCED MODERN BLOG THEME
   Sophisticated typography, visual hierarchy, 
   and professional design elements
   ============================================ */

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

:root {
  /* Layout */
  --header-h: 60px;
  --wrap: 880px;
  --wrap-narrow: 720px;

  /* Colors - Dark theme with accent gradients */
  --bg-primary: #0a0e1a;
  --bg-secondary: #0f1629;
  --bg-tertiary: #1a2238;
  --text-primary: #e9eefb;
  --text-secondary: #b6c5e1;
  --text-muted: #8794b3;
  --text-bright: #f8fbff;
  --accent-blue: #7aa2ff;
  --accent-cyan: #7affd1;
  --accent-purple: #a78bfa;
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-medium: rgba(255, 255, 255, 0.15);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.25s ease;
  --transition-slow: 0.4s ease;
}

/* Base Typography */
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  color: var(--text-primary);
  background: #000;
  font-family: 'Inter', ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  font-size: 18px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  position: relative;
}

/* Headings */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text-bright);
}

h1 {
  font-size: clamp(2.25rem, 5.5vw, 3.5rem);
  margin: 0.25rem 0 0.5rem;
  font-weight: 900;
}

h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  margin: 2.5rem 0 1rem;
  color: #f0f5ff;
}

h3 {
  font-size: clamp(1.15rem, 2.5vw, 1.5rem);
  margin: 1.75rem 0 0.75rem;
  color: var(--text-bright);
}

.h5 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 1.25rem 0 0.5rem;
  color: var(--accent-cyan);
}

/* Prose Content */
p {
  margin: 1rem 0;
  line-height: 1.75;
}

.lede {
  font-size: 1.25rem;
  line-height: 1.65;
  color: var(--text-bright);
  font-weight: 500;
  margin: 1.25rem 0;
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: all var(--transition-fast);
}

a:hover {
  color: var(--accent-blue);
  border-bottom-color: var(--accent-blue);
}

strong {
  font-weight: 700;
  color: var(--text-bright);
}

em {
  font-style: italic;
  color: var(--text-bright);
}

/* Layout Wrappers */
.wrap {
  width: min(var(--wrap), 94%);
  margin-inline: auto;
  position: relative;
  z-index: 1;
}

.small {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Decorative Background */
.decor-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.decor-bg::before,
.decor-bg::after {
  content: "";
  position: absolute;
  width: 1000px;
  height: 1000px;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.15;
}

.decor-bg::before {
  top: -500px;
  left: -500px;
  background: radial-gradient(circle, var(--accent-blue) 0%, transparent 70%);
}

.decor-bg::after {
  bottom: -500px;
  right: -400px;
  background: radial-gradient(circle, var(--accent-purple) 0%, transparent 70%);
}

/* Progress Bar */
.progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 10000;
  background: rgba(255, 255, 255, 0.05);
}

.progress .bar {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan));
  transition: width 0.1s linear;
  box-shadow: 0 0 10px var(--accent-cyan);
}

/* Header */
.blog-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  z-index: 9990;
  background: rgba(10, 14, 26, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

.blog-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0;
}

.brand {
  display: inline-block;
  font-weight: 900;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--text-bright);
  transition: all var(--transition-fast);
}

.brand:hover {
  color: var(--accent-cyan);
  border: none;
}

.brand span {
  color: var(--accent-blue);
}

.topnav {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.topnav .nav {
  display: inline-block;
  padding: 0.5rem 0.85rem;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: 0.5rem;
  font-size: 0.95rem;
  font-weight: 500;
  transition: all var(--transition-fast);
  border-bottom: none;
}

.topnav .nav:hover,
.topnav .nav.active {
  color: var(--text-bright);
  background: rgba(122, 162, 255, 0.15);
  border-bottom: none;
}

.topnav .cta-nav {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: var(--bg-primary);
  font-weight: 700;
}

.topnav .cta-nav:hover {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(122, 162, 255, 0.3);
}

/* Main Content */
.post {
  padding: calc(var(--header-h) + 2rem) 0 4rem;
  min-height: 100vh;
}

/* Entry Header */
.entry-header {
  margin-bottom: 2.5rem;
  text-align: left;
}

.entry-header h1 {
  background: linear-gradient(135deg, var(--text-bright), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.75rem;
}

.meta {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin: 0.5rem 0;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.topic-tags {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.tag {
  display: inline-block;
  padding: 0.35rem 0.75rem;
  background: rgba(122, 162, 255, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(122, 162, 255, 0.2);
  border-radius: 1rem;
  font-size: 0.85rem;
  font-weight: 600;
}

/* Sections */
.section {
  margin: 3rem 0;
  scroll-margin-top: calc(var(--header-h) + 2rem);
}

/* Hero Section */
.hero-section {
  text-align: center;
  padding: 2rem 0;
  margin-bottom: 4rem;
}

.hero-section .entry-header h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  margin-bottom: 1.5rem;
}

.hero-section .lede {
  max-width: 820px;
  margin-left: auto;
  margin-right: auto;
  font-size: 1.35rem;
}

.hero-section .topic-tags {
  justify-content: center;
  margin-top: 2rem;
}

/* CTA Section */
.cta-section {
  text-align: center;
  padding: 3rem 0;
  margin: 4rem 0;
}

.cta-section h2 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  margin-bottom: 1rem;
}

/* Era Highlights */
.era-highlight {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: linear-gradient(135deg, rgba(122, 162, 255, 0.08), rgba(122, 255, 209, 0.08));
  border-left: 4px solid var(--accent-blue);
  border-radius: 0.5rem;
  margin: 1.5rem 0;
}

.era-badge {
  background: var(--accent-blue);
  color: var(--bg-primary);
  padding: 0.35rem 0.85rem;
  border-radius: 0.4rem;
  font-weight: 800;
  font-size: 0.9rem;
  white-space: nowrap;
  flex-shrink: 0;
}

.era-highlight p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

/* Stats Box */
.stats-box {
  background: rgba(122, 162, 255, 0.05);
  border: 1px solid var(--border-subtle);
  border-radius: 0.75rem;
  padding: 1.5rem;
  margin: 2rem 0;
}

.stat-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
}

.stat-list li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.95rem;
}

.stat-list li:last-child {
  border-bottom: none;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 0.5rem;
  margin: 1.5rem 0 0;
  border-bottom: 2px solid var(--border-subtle);
}

.tab-btn {
  background: transparent;
  border: none;
  border-bottom: 3px solid transparent;
  padding: 0.75rem 1.25rem;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 600;
  transition: all var(--transition-fast);
  position: relative;
  bottom: -2px;
}

.tab-btn:hover {
  color: var(--text-bright);
  background: rgba(255, 255, 255, 0.03);
}

.tab-btn.is-active {
  color: var(--accent-cyan);
  border-bottom-color: var(--accent-cyan);
}

.tab-panels {
  margin-top: 0;
}

.tab-panel {
  display: none;
  padding: 1.5rem 0 1rem 1rem;
  border-left: 3px solid var(--accent-blue);
  margin-left: 0.5rem;
}

.tab-panel.is-active {
  display: block;
  animation: fadeIn 0.3s ease;
}

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

.tab-panel li {
  padding: 0.65rem 0;
  padding-left: 1.5rem;
  position: relative;
}

.tab-panel li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--accent-cyan);
  font-weight: bold;
}

/* Accordion */
.accordion {
  margin: 1.5rem 0;
}

.acc-btn {
  width: 100%;
  text-align: left;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: 0.6rem;
  padding: 1rem 1.25rem;
  margin-top: 0.75rem;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  transition: all var(--transition-base);
  position: relative;
  padding-right: 3rem;
}

.acc-btn::after {
  content: "＋";
  position: absolute;
  right: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.25rem;
  transition: transform var(--transition-base);
  color: var(--accent-blue);
}

.acc-btn.open::after {
  transform: translateY(-50%) rotate(45deg);
}

.acc-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--border-medium);
}

.acc-panel {
  display: none;
  padding: 1.25rem;
  margin-top: 0.5rem;
  border-left: 3px solid var(--accent-cyan);
  background: rgba(122, 255, 209, 0.05);
  border-radius: 0 0.5rem 0.5rem 0;
  margin-left: 0.5rem;
}

.acc-panel p {
  margin: 0;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Interactive Comparison Grid */
.interactive-comparison {
  margin: 2rem 0;
  padding: 1.5rem;
  background: rgba(167, 139, 250, 0.05);
  border: 1px solid rgba(167, 139, 250, 0.2);
  border-radius: 0.75rem;
}

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin: 1rem 0;
}

.compare-btn {
  background: linear-gradient(135deg, rgba(122, 162, 255, 0.15), rgba(167, 139, 250, 0.15));
  border: 1px solid var(--border-medium);
  border-radius: 0.5rem;
  padding: 0.85rem 1rem;
  color: var(--text-bright);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  text-align: center;
}

.compare-btn:hover {
  background: linear-gradient(135deg, rgba(122, 162, 255, 0.25), rgba(167, 139, 250, 0.25));
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.compare-btn.active {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: var(--bg-primary);
}

.feature-panel {
  min-height: 100px;
  padding: 1.25rem;
  margin-top: 1rem;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 0.5rem;
  border: 1px solid var(--border-subtle);
}

.prompt-text {
  color: var(--text-muted);
  font-style: italic;
  text-align: center;
  margin: 2rem 0;
}

/* Quiz */
.quiz {
  margin: 2rem 0;
  padding: 1.75rem;
  background: linear-gradient(135deg, rgba(122, 162, 255, 0.08), rgba(122, 255, 209, 0.08));
  border: 1px dashed var(--border-medium);
  border-radius: 0.75rem;
}

.quiz label {
  display: block;
  padding: 0.65rem 0;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.quiz label:hover {
  color: var(--accent-cyan);
}

.quiz input[type="radio"] {
  margin-right: 0.5rem;
  cursor: pointer;
}

.quiz-actions {
  margin-top: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.quiz-actions button {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: var(--bg-primary);
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 0.5rem;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: 0 2px 8px rgba(122, 162, 255, 0.3);
}

.quiz-actions button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(122, 162, 255, 0.4);
}

#quiz-result {
  min-height: 1.5rem;
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 0.95rem;
}

/* Media - Images & Video */
.image-content,
.timeline-visual {
  margin: 2rem 0;
}

.image-content img,
.timeline-visual img {
  width: 100%;
  height: auto;
  border-radius: 0.75rem;
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-lg);
}

figcaption,
.caption {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 0.75rem;
  font-style: italic;
}

.video-explainer {
  margin: 2.5rem 0;
}

.media-embed {
  margin: 2rem 0;
}

.video {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  border-radius: 0.75rem;
  border: 1px solid var(--border-medium);
  box-shadow: var(--shadow-lg);
  background: var(--bg-secondary);
}

.video iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* Pullquote */
.pullquote {
  margin: 2.5rem 0;
  padding: 2rem;
  border-left: 5px solid var(--accent-purple);
  background: linear-gradient(135deg, rgba(167, 139, 250, 0.05), transparent);
  border-radius: 0 0.75rem 0.75rem 0;
}

.pullquote blockquote {
  margin: 0;
}

.pullquote p {
  font-size: 1.25rem;
  line-height: 1.6;
  font-style: italic;
  color: var(--text-bright);
  margin: 0;
}

/* Key Takeaways */
.key-takeaways {
  margin: 2rem 0;
  padding: 1.75rem;
  background: rgba(122, 255, 209, 0.05);
  border: 2px solid var(--accent-cyan);
  border-radius: 0.75rem;
}

.key-takeaways ul {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
}

.key-takeaways li {
  padding: 0.85rem 0;
  padding-left: 2rem;
  position: relative;
  border-bottom: 1px solid var(--border-subtle);
}

.key-takeaways li:last-child {
  border-bottom: none;
}

.key-takeaways li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent-cyan);
  font-weight: bold;
  font-size: 1.25rem;
}

/* References */
.refs {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
}

.refs li {
  padding: 0.85rem 0;
  padding-left: 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
  position: relative;
}

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

.refs li::before {
  content: "📄";
  position: absolute;
  left: 0;
  top: 0.85rem;
}

.attribution-note {
  margin-top: 2rem;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 0.5rem;
  font-size: 0.9rem;
  line-height: 1.6;
}

/* Footer */
.blog-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2.5rem 0;
  margin-top: 4rem;
  background: rgba(10, 14, 26, 0.5);
}

.blog-footer p {
  margin: 0.5rem 0;
  font-size: 0.9rem;
}

.back-top {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  background: rgba(122, 162, 255, 0.1);
  border: 1px solid var(--accent-blue);
  border-radius: 0.5rem;
  color: var(--accent-cyan);
  text-decoration: none;
  transition: all var(--transition-base);
}

.back-top:hover {
  background: rgba(122, 162, 255, 0.2);
  transform: translateY(-2px);
  border-bottom: 1px solid var(--accent-blue);
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsive Adjustments */
@media (max-width: 768px) {
  .blog-header .wrap {
    flex-direction: column;
    gap: 0.75rem;
  }

  .topnav {
    width: 100%;
    justify-content: center;
    flex-wrap: wrap;
  }

  .era-highlight {
    flex-direction: column;
    align-items: flex-start;
  }

  .comparison-grid {
    grid-template-columns: 1fr;
  }
}

/* Print Styles */
@media print {

  .blog-header,
  .progress,
  .decor-bg,
  .back-top {
    display: none;
  }

  body {
    color: #000;
    background: #fff;
  }
}

/* WhatsApp CTA Button */
.whatsapp-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.6rem;
  border-radius: 999px;
  background: linear-gradient(135deg, #25D366, var(--accent-cyan));
  color: #020617;
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  box-shadow: 0 6px 18px rgba(37, 211, 102, 0.45);
  transition: transform 0.18s ease, box-shadow 0.18s ease, filter 0.18s ease;
}

.whatsapp-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 26px rgba(37, 211, 102, 0.6);
  filter: brightness(1.05);
}

/* Footer WhatsApp + QR layout */
.footer-contact {
  margin-top: 1.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  align-items: center;
}

.footer-whatsapp {
  max-width: 380px;
}

.footer-qr {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.qr-image {
  width: 160px;
  height: auto;
  border-radius: 1rem;
  border: 1px solid var(--border-subtle);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.55);
}

.qr-caption {
  margin-top: 0.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

@media (max-width: 640px) {
  .footer-contact {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-qr {
    align-items: flex-start;
  }
}