/* AISimply — Design System */
/* Niche blog: Tech & AI for beginners */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

:root {
  /* Colors — Dark theme (default) */
  --bg-primary: #0f1117;
  --bg-secondary: #1a1d27;
  --bg-card: #1e2130;
  --bg-hover: #252838;
  --text-primary: #e8eaed;
  --text-secondary: #9aa0b0;
  --text-muted: #6b7280;
  --accent: #6c5ce7;
  --accent-light: #a29bfe;
  --accent-glow: rgba(108, 92, 231, 0.15);
  --border: #2d3045;
  --border-light: #383b50;
  --success: #00b894;
  --warning: #fdcb6e;
  --danger: #e17055;
  --link: #74b9ff;
  --link-hover: #a29bfe;
  --code-bg: #161822;
  --shadow: 0 4px 20px rgba(0,0,0,0.3);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --max-width: 1200px;
  --content-width: 720px;
  --transition: 0.2s ease;
  --gradient: linear-gradient(135deg, #6c5ce7, #a29bfe);
  --gradient-text: linear-gradient(135deg, #a29bfe, #74b9ff);
}

[data-theme="light"] {
  --bg-primary: #f8f9fc;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-hover: #f0f2f8;
  --text-primary: #1a1d2e;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --border: #e2e8f0;
  --border-light: #edf2f7;
  --code-bg: #f1f3f9;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.05);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
  color: var(--text-primary);
}
h1 { font-size: 2.2rem; font-weight: 800; }
h2 { font-size: 1.6rem; margin-top: 2rem; }
h3 { font-size: 1.25rem; margin-top: 1.5rem; }

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

p { margin-bottom: 1rem; color: var(--text-secondary); }

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

/* Layout */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; width: 100%; }
.content-container { max-width: var(--content-width); margin: 0 auto; }

/* Header */
.site-header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}
.site-logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.site-logo .logo-icon {
  width: 32px;
  height: 32px;
  background: var(--gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}
.site-logo:hover { color: var(--accent-light); }

.header-nav { display: flex; align-items: center; gap: 1.5rem; }
.header-nav a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.4rem 0;
  border-bottom: 2px solid transparent;
  transition: all var(--transition);
}
.header-nav a:hover, .header-nav a.active {
  color: var(--text-primary);
  border-bottom-color: var(--accent);
}

.header-actions { display: flex; align-items: center; gap: 0.75rem; }

/* Theme toggle */
.theme-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: all var(--transition);
  display: flex;
  align-items: center;
}
.theme-toggle:hover { background: var(--bg-hover); color: var(--text-primary); }

/* Language toggle */
.lang-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.6rem;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 600;
  transition: all var(--transition);
  text-transform: uppercase;
}
.lang-toggle:hover { background: var(--bg-hover); color: var(--text-primary); }

/* Mobile nav */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.25rem;
}

/* Hero section */
.hero {
  padding: 4rem 0 3rem;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}
.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}
.hero-gradient {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2rem;
}
.hero-stat { text-align: center; }
.hero-stat .number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-light);
  display: block;
}
.hero-stat .label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* Search bar */
.search-container {
  max-width: 500px;
  margin: 2rem auto 0;
  position: relative;
}
.search-input {
  width: 100%;
  padding: 0.8rem 1.2rem 0.8rem 2.8rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: all var(--transition);
}
.search-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }
.search-input::placeholder { color: var(--text-muted); }
.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 1rem;
}

/* Category filters */
.category-filters {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin: 2rem 0;
  padding: 0 1rem;
}
.category-btn {
  padding: 0.5rem 1.2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}
.category-btn:hover { background: var(--bg-hover); color: var(--text-primary); }
.category-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* Article cards grid */
.articles-section { padding: 2rem 0 4rem; }
.articles-section h2 { margin-bottom: 1.5rem; }

.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}
.article-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: var(--accent);
}
.article-card .card-category {
  display: inline-block;
  padding: 0.2rem 0.7rem;
  background: var(--accent-glow);
  color: var(--accent-light);
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  width: fit-content;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.article-card h3 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  line-height: 1.4;
}
.article-card h3 a { color: var(--text-primary); }
.article-card h3 a:hover { color: var(--accent-light); }
.article-card .card-excerpt {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 1rem;
}
.article-card .card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}
.card-meta .reading-time { display: flex; align-items: center; gap: 0.3rem; }

/* Featured article */
.featured-article {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}
.featured-article::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient);
}
.featured-badge {
  display: inline-block;
  padding: 0.3rem 0.8rem;
  background: var(--gradient);
  color: #fff;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.featured-article h2 {
  font-size: 1.8rem;
  margin: 0 0 0.75rem;
}
.featured-article h2 a { color: var(--text-primary); }
.featured-article h2 a:hover { color: var(--accent-light); }
.featured-article .card-excerpt { font-size: 1rem; color: var(--text-secondary); }

/* Article page */
.article-page { padding: 2rem 0 4rem; }

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}
.article-header h1 {
  font-size: 2.2rem;
  margin-bottom: 1rem;
  letter-spacing: -0.01em;
}
.article-meta {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  color: var(--text-muted);
  font-size: 0.9rem;
  flex-wrap: wrap;
}
.article-meta span { display: flex; align-items: center; gap: 0.3rem; }

/* Reading progress bar */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--gradient);
  z-index: 200;
  transition: width 0.1s linear;
}

/* Table of Contents */
.toc {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 2rem;
}
.toc h2 {
  font-size: 1rem;
  margin: 0 0 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}
.toc ul { list-style: none; }
.toc li { margin-bottom: 0.4rem; }
.toc a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.25rem 0;
}
.toc a::before { content: '#'; color: var(--accent); font-weight: 600; opacity: 0.5; }
.toc a:hover { color: var(--accent-light); }

/* Article body */
.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
}
.article-body h2 {
  font-size: 1.5rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-top: 1rem;
}
.article-body h3 {
  font-size: 1.2rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}
.article-body p {
  margin-bottom: 1.2rem;
  color: var(--text-secondary);
}
.article-body ul, .article-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--text-secondary);
}
.article-body li { margin-bottom: 0.5rem; line-height: 1.7; }
.article-body strong { color: var(--text-primary); font-weight: 600; }
.article-body blockquote {
  border-left: 3px solid var(--accent);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  background: var(--accent-glow);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
  font-style: italic;
}
.article-body code {
  background: var(--code-bg);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--accent-light);
}
.article-body pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.2rem;
  overflow-x: auto;
  margin: 1.5rem 0;
}
.article-body pre code { background: none; padding: 0; }
.article-body a { text-decoration: underline; text-underline-offset: 2px; }
.article-body a:hover { text-decoration-color: var(--accent); }

/* Comparison table */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}
.comparison-table th {
  background: var(--bg-secondary);
  padding: 0.8rem 1rem;
  text-align: left;
  border-bottom: 2px solid var(--accent);
  font-weight: 600;
  color: var(--text-primary);
}
.comparison-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
}
.comparison-table tr:hover td { background: var(--bg-hover); }

/* Key takeaway box */
.key-takeaway {
  background: var(--accent-glow);
  border: 1px solid rgba(108, 92, 231, 0.3);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin: 2rem 0;
}
.key-takeaway h4 {
  color: var(--accent-light);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

/* FAQ Section */
.faq { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--border); }
.faq h2 { margin-bottom: 1.5rem; }
.faq-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 0.75rem;
  overflow: hidden;
}
.faq-question {
  width: 100%;
  background: none;
  border: none;
  padding: 1rem 1.2rem;
  text-align: left;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: inherit;
  transition: background var(--transition);
}
.faq-question:hover { background: var(--bg-hover); }
.faq-question::after { content: '+'; font-size: 1.2rem; color: var(--accent); transition: transform var(--transition); }
.faq-item.open .faq-question::after { content: '\2212'; }
.faq-answer {
  padding: 0 1.2rem;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}
.faq-item.open .faq-answer { max-height: 500px; padding-bottom: 1rem; }

/* Related articles */
.related-articles { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--border); }
.related-articles h2 { margin-bottom: 1.5rem; }
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}
.related-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.2rem;
  transition: all var(--transition);
}
.related-card:hover { border-color: var(--accent); }
.related-card h4 { font-size: 0.95rem; margin-bottom: 0.3rem; }
.related-card h4 a { color: var(--text-primary); }
.related-card p { font-size: 0.8rem; color: var(--text-muted); margin: 0; }

/* Ad slots */
.ad-slot {
  margin: 2rem 0;
  text-align: center;
  min-height: 90px;
  overflow: hidden;
}
.ad-slot .adsbygoogle { display: block; }
/* Hide ad slots when AdSense is not active */
.ad-slot:empty { display: none; }
.ad-slot:has(> .adsbygoogle[data-ad-status="unfilled"]) { display: none; }

/* Author box */
.author-box {
  display: flex;
  gap: 1.2rem;
  align-items: flex-start;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin: 2.5rem 0;
}
.author-avatar {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  flex-shrink: 0;
  color: #fff;
  font-weight: 700;
}
.author-info { flex: 1; }
.author-info .author-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}
.author-info .author-role {
  font-size: 0.8rem;
  color: var(--accent-light);
  margin-bottom: 0.5rem;
}
.author-info .author-bio {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 0.5rem;
}
.author-links { display: flex; gap: 0.8rem; flex-wrap: wrap; }
.author-links a {
  font-size: 0.78rem;
  color: var(--link);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}
.author-links a:hover { color: var(--link-hover); }

/* E-E-A-T signals */
.eeat-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem 1.5rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.5rem;
}
.eeat-bar span { display: flex; align-items: center; gap: 0.3rem; }

/* Author's take callout */
.author-take {
  background: var(--accent-glow);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 1rem 1.2rem;
  margin: 1.8rem 0;
  font-size: 0.92rem;
  line-height: 1.6;
}
.author-take .take-label {
  font-weight: 700;
  color: var(--accent-light);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.4rem;
}
.author-take p {
  color: var(--text-primary);
  margin: 0;
}

/* Sources section */
.article-sources {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.2rem;
  margin: 2rem 0;
  font-size: 0.82rem;
}
.article-sources h3 {
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.6rem;
}
.article-sources ul { list-style: none; padding: 0; margin: 0; }
.article-sources li {
  padding: 0.3rem 0;
  color: var(--text-muted);
}
.article-sources a { color: var(--link); text-decoration: none; }
.article-sources a:hover { text-decoration: underline; }

/* Methodology note */
.methodology-note {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-style: italic;
  padding: 0.8rem 0;
  border-top: 1px solid var(--border);
  margin-top: 1.5rem;
}

@media (max-width: 600px) {
  .author-box { flex-direction: column; align-items: center; text-align: center; }
  .author-links { justify-content: center; }
}

/* Newsletter signup */
.newsletter-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  margin: 2.5rem 0;
}
.newsletter-box h3 { margin-bottom: 0.5rem; font-size: 1.2rem; }
.newsletter-box p { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 1rem; }
.newsletter-form { display: flex; gap: 0.5rem; max-width: 400px; margin: 0 auto; }
.newsletter-form input {
  flex: 1;
  padding: 0.6rem 1rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.9rem;
  outline: none;
}
.newsletter-form input:focus { border-color: var(--accent); }
.newsletter-form button {
  padding: 0.6rem 1.2rem;
  background: var(--gradient);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.9rem;
  transition: opacity var(--transition);
}
.newsletter-form button:hover { opacity: 0.9; }

/* Category page */
.category-page { padding: 2rem 0 4rem; }
.category-header {
  text-align: center;
  padding: 2rem 0 1rem;
}
.category-header h1 { font-size: 2rem; margin-bottom: 0.5rem; }
.category-header p { color: var(--text-muted); font-size: 1rem; }
.category-count {
  display: inline-block;
  padding: 0.3rem 0.8rem;
  background: var(--accent-glow);
  color: var(--accent-light);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 0.5rem;
}

/* Blog index */
.blog-header { text-align: center; padding: 3rem 0 1rem; }
.blog-header h1 { margin-bottom: 0.5rem; }

/* Breadcrumb */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent-light); }
.breadcrumb .separator { color: var(--border); }

/* Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
  margin-top: auto;
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
}
.footer-brand p { color: var(--text-muted); font-size: 0.85rem; margin-top: 0.5rem; line-height: 1.6; }
.footer-col h4 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 0.4rem; }
.footer-col a { color: var(--text-secondary); font-size: 0.85rem; }
.footer-col a:hover { color: var(--accent-light); }
.footer-bottom {
  max-width: var(--max-width);
  margin: 2rem auto 0;
  padding: 1.5rem 1.5rem 0;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.footer-bottom a { color: var(--text-muted); }
.footer-bottom a:hover { color: var(--accent-light); }

/* Pagination */
.pagination {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 2rem;
}
.page-btn {
  padding: 0.5rem 0.9rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.85rem;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition);
}
.page-btn:hover { border-color: var(--accent); color: var(--text-primary); }
.page-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* About page */
.about-page { padding: 2rem 0 4rem; }
.about-content { max-width: var(--content-width); margin: 0 auto; }
.about-content h1 { margin-bottom: 1.5rem; }
.about-content h2 { margin-top: 2rem; margin-bottom: 0.75rem; font-size: 1.3rem; }

/* 404 page */
.page-404 { text-align: center; padding: 6rem 0; }
.page-404 h1 { font-size: 5rem; color: var(--accent); margin-bottom: 0.5rem; }
.page-404 p { font-size: 1.1rem; color: var(--text-muted); margin-bottom: 2rem; }
.btn-home {
  display: inline-block;
  padding: 0.7rem 1.5rem;
  background: var(--gradient);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: opacity var(--transition);
}
.btn-home:hover { opacity: 0.9; color: #fff; }

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px;
  height: 40px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.2rem;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 50;
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
}
.back-to-top.visible { display: flex; }
.back-to-top:hover { transform: translateY(-2px); }

/* Responsive */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .hero-stats { gap: 1.5rem; }
  .hero-stat .number { font-size: 1.5rem; }
  .article-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 1.5rem; }
  .footer-bottom { flex-direction: column; gap: 0.5rem; text-align: center; }
  .header-nav { display: none; }
  .header-nav.open { display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; background: var(--bg-secondary); border-bottom: 1px solid var(--border); padding: 1rem 1.5rem; gap: 0.5rem; }
  .mobile-menu-btn { display: block; }
  .article-header h1 { font-size: 1.7rem; }
  .featured-article { padding: 1.5rem; }
  .featured-article h2 { font-size: 1.4rem; }
  .newsletter-form { flex-direction: column; }
  .related-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.6rem; }
  .hero-stats { flex-direction: column; gap: 1rem; }
  .footer-inner { grid-template-columns: 1fr; }
  .category-filters { gap: 0.3rem; }
  .category-btn { padding: 0.4rem 0.8rem; font-size: 0.8rem; }
}

/* Print styles */
@media print {
  .site-header, .site-footer, .ad-slot, .back-to-top, .newsletter-box, .theme-toggle, .lang-toggle { display: none !important; }
  body { background: #fff; color: #000; }
  .article-body a { color: #000; text-decoration: underline; }
  .article-body a::after { content: ' (' attr(href) ')'; font-size: 0.8em; }
}