/* ===== InfoPedia Global Styles ===== */
/* Material Design inspired, clean white */

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

:root {
  --primary: #1a73ed;
  --primary-dark: #1557b0;
  --text: #202124;
  --text-secondary: #5f6368;
  --bg: #fff;
  --bg-gray: #f8f9fa;
  --border: #dadce0;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --radius-sm: 8px;
  --max-width: 1100px;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

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

/* ===== Typography ===== */
h1, h2, h3, h4 {
  color: var(--text);
  line-height: 1.3;
  font-weight: 600;
}

h1 { font-size: 2rem; margin-bottom: 0.5rem; }
h2 { font-size: 1.5rem; margin: 1.5rem 0 0.75rem; }
h3 { font-size: 1.2rem; margin: 1.25rem 0 0.5rem; }

p { margin-bottom: 1rem; }

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

ul, ol {
  margin: 0.75rem 0 1rem 1.5rem;
}
li {
  margin-bottom: 0.5rem;
}

/* ===== Header / Navigation ===== */
.site-header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  height: 60px;
}

.site-header .logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 8px;
}
.site-header .logo:hover {
  text-decoration: none;
  color: var(--primary-dark);
}
.site-header .logo .logo-icon {
  font-size: 1.6rem;
}

.site-header .nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
  margin: 0;
}
.site-header .nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}
.site-header .nav-links a:hover,
.site-header .nav-links a.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  text-decoration: none;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
}

/* ===== Layout ===== */
.site-main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 20px;
}

.main-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 32px;
  align-items: start;
}

.main-content {
  min-width: 0;
}

/* ===== Sidebar ===== */
.sidebar {
  position: sticky;
  top: 80px;
}
.sidebar .sidebar-section {
  margin-bottom: 24px;
}
.sidebar .sidebar-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-secondary);
  margin-bottom: 12px;
  font-weight: 600;
}

/* ===== Category Cards (Homepage) ===== */
.category-section {
  margin-bottom: 40px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.section-title .cat-emoji {
  font-size: 1.6rem;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}

.category-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: box-shadow 0.2s, transform 0.2s;
}
.category-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}
.category-card .card-header {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.category-card .card-links {
  list-style: none;
  margin: 0;
}
.category-card .card-links li {
  margin-bottom: 6px;
}
.category-card .card-links a {
  font-size: 0.95rem;
  color: var(--text);
  display: block;
  padding: 6px 8px;
  border-radius: 6px;
  transition: background 0.15s;
}
.category-card .card-links a:hover {
  background: var(--bg-gray);
  color: var(--primary);
  text-decoration: none;
}

/* ===== Search ===== */
.search-container {
  margin-bottom: 32px;
}

.search-input {
  width: 100%;
  padding: 14px 18px;
  font-size: 1rem;
  border: 2px solid var(--border);
  border-radius: 28px;
  outline: none;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.search-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 115, 237, 0.15);
}
.search-input::placeholder {
  color: #9aa0a6;
}

.no-results {
  display: none;
  text-align: center;
  padding: 32px;
  color: var(--text-secondary);
}

/* ===== Breadcrumbs ===== */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
}
.breadcrumbs a {
  color: var(--text-secondary);
}
.breadcrumbs a:hover {
  color: var(--primary);
}
.breadcrumbs .separator {
  color: #9aa0a6;
}

/* ===== Article ===== */
article {
  max-width: 750px;
}

article .article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
article .article-meta .author {
  font-weight: 500;
  color: var(--text);
}
article .article-meta .meta-sep {
  color: #9aa0a6;
}

/* Image Placeholder */
.img-placeholder {
  background: linear-gradient(135deg, #e8f0fe 0%, #d2e3fc 50%, #e8f0fe 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 200px;
  margin: 20px 0;
  font-size: 4rem;
  color: var(--primary);
  opacity: 0.7;
  overflow: hidden;
  position: relative;
}
.img-placeholder.small {
  min-height: 140px;
  font-size: 3rem;
}
.img-placeholder::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.4) 0%, transparent 60%);
}

/* ===== Advertisement ===== */
.ad-container {
  margin: 20px 0;
}

/* ===== Related Articles ===== */
.related-articles {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}
.related-articles h3 {
  font-size: 1.3rem;
  margin-bottom: 16px;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
}
.related-card {
  background: var(--bg-gray);
  padding: 16px;
  border-radius: var(--radius-sm);
  transition: background 0.15s;
}
.related-card:hover {
  background: #e8f0fe;
}
.related-card a {
  color: var(--text);
  font-weight: 500;
  font-size: 0.95rem;
}
.related-card a:hover {
  color: var(--primary);
  text-decoration: none;
}

/* ===== Recent Updates (Homepage) ===== */
.recent-updates {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.recent-updates h2 {
  font-size: 1.3rem;
  margin-bottom: 16px;
}
.recent-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 12px;
}
.recent-item {
  background: var(--bg-gray);
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.recent-item a {
  font-weight: 500;
  color: var(--text);
}
.recent-item a:hover {
  color: var(--primary);
  text-decoration: none;
}
.recent-item .recent-date {
  font-size: 0.8rem;
  color: var(--text-secondary);
  white-space: nowrap;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--bg-gray);
  border-top: 1px solid var(--border);
  margin-top: 48px;
  padding: 32px 20px;
}
.site-footer .footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.site-footer .footer-brand {
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.9rem;
}
.site-footer .footer-links {
  display: flex;
  gap: 20px;
  list-style: none;
  margin: 0;
}
.site-footer .footer-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}
.site-footer .footer-links a:hover {
  color: var(--primary);
  text-decoration: none;
}

/* ===== Placeholder Pages ===== */
.placeholder-page {
  text-align: center;
  padding: 60px 20px;
}
.placeholder-page h1 {
  font-size: 2rem;
  margin-bottom: 12px;
}
.placeholder-page p {
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto 24px;
}
.placeholder-page .btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 10px 24px;
  border-radius: 24px;
  font-weight: 500;
  transition: background 0.2s;
}
.placeholder-page .btn:hover {
  background: var(--primary-dark);
  text-decoration: none;
  color: #fff;
}

/* ===== Tips / Info boxes ===== */
.tip-box {
  background: #e8f0fe;
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
}
.tip-box strong {
  display: block;
  margin-bottom: 4px;
  color: var(--primary);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .main-with-sidebar {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
  }

  .site-header .nav-links {
    display: none;
  }

  .site-header .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 20px;
    gap: 12px;
  }

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

  h1 { font-size: 1.6rem; }
  h2 { font-size: 1.3rem; }

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

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

  article {
    max-width: 100%;
  }

  .img-placeholder {
    min-height: 160px;
    font-size: 3rem;
  }

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

@media (max-width: 480px) {
  .related-grid {
    grid-template-columns: 1fr;
  }

  .recent-list {
    grid-template-columns: 1fr;
  }

  .article-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
}