/**
 * Blog design system & components
 * Uses and extends existing :root vars from styles.css; adds blog-specific and dark mode.
 */
:root {
  /* Design system (extend existing) */
  --color-primary: var(--primary-color, #065a45);
  --color-accent: var(--brand-blue, #0189b0);
  --color-bg: var(--bg-white, #ffffff);
  --color-bg-alt: var(--bg-light, #fafafa);
  --color-text: var(--text-dark, #1a1a1a);
  --color-muted: var(--text-light, #666666);
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-heading: var(--font-body);
  --font-mono: ui-monospace, 'Cascadia Code', 'Source Code Pro', monospace;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.08);
  --transition: all 0.2s ease;
}

@media (prefers-color-scheme: dark) {
  [data-theme="auto"] {
    --color-bg: #121212;
    --color-bg-alt: #1e1e1e;
    --color-text: #e5e5e5;
    --color-muted: #a3a3a3;
    --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.3);
  }
}

[data-theme="light"] {
  --color-bg: #ffffff;
  --color-bg-alt: #fafafa;
  --color-text: #1a1a1a;
  --color-muted: #666666;
}

[data-theme="dark"] {
  --color-bg: #121212;
  --color-bg-alt: #1e1e1e;
  --color-text: #e5e5e5;
  --color-muted: #a3a3a3;
  --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* Dark mode toggle */
.blog-theme-toggle {
  background: none;
  border: 1px solid var(--color-muted);
  border-radius: var(--radius-md);
  color: var(--color-text);
  cursor: pointer;
  padding: var(--space-sm) var(--space-md);
  font-size: 0.875rem;
  min-width: 44px;
  min-height: 44px;
}
.blog-theme-toggle:hover { opacity: 0.9; }

/* Utility */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

/* ----- Blog listing ----- */
.blog-listing-page { padding-top: 90px; min-height: 100vh; }
.blog-listing-hero {
  padding: var(--space-2xl) 0;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--border-color, #e5e5e5);
}
.blog-listing-title { font-size: clamp(2rem, 5vw, 3rem); margin-bottom: var(--space-sm); }
.blog-listing-subtitle { font-size: 1.125rem; color: var(--color-muted); }

.blog-listing-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: center;
  padding: var(--space-lg) 0;
}
.blog-search-wrap { flex: 1; min-width: 200px; }
.blog-search-input {
  width: 100%;
  max-width: 320px;
  padding: var(--space-md) var(--space-lg);
  border: 1px solid var(--border-color, #e5e5e5);
  border-radius: var(--radius-md);
  font-size: 1rem;
  background: var(--color-bg);
  color: var(--color-text);
}
.blog-filters { display: flex; flex-wrap: wrap; gap: var(--space-sm); }
.blog-filter-select {
  padding: var(--space-md) var(--space-lg);
  border: 1px solid var(--border-color, #e5e5e5);
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 44px;
}

/* Grid: 3 → 2 → 1 */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  list-style: none;
  padding: 0;
  margin: 0;
}
@media (max-width: 992px) {
  .blog-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 576px) {
  .blog-grid { grid-template-columns: 1fr; gap: var(--space-lg); }
}

.blog-card {
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}
.blog-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}
.blog-card-link {
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  height: 100%;
}
.blog-card-thumb {
  aspect-ratio: 16 / 10;
  object-fit: cover;
  width: 100%;
  background: var(--color-bg-alt);
}
.blog-card-body { padding: var(--space-lg); flex: 1; display: flex; flex-direction: column; }
.blog-card-category {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}
.blog-card-title { font-size: 1.25rem; margin-bottom: var(--space-sm); line-height: 1.3; }
.blog-card-excerpt { font-size: 0.9375rem; color: var(--color-muted); margin-bottom: var(--space-md); flex: 1; }
.blog-card-meta { font-size: 0.875rem; color: var(--color-muted); }
.blog-card-read { font-size: 0.875rem; font-weight: 600; color: var(--color-primary); margin-top: var(--space-sm); }

/* Skeleton */
.blog-skeleton {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}
@media (max-width: 992px) { .blog-skeleton { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 576px) { .blog-skeleton { grid-template-columns: 1fr; } }
.blog-card-skeleton {
  height: 280px;
  border-radius: var(--radius-lg);
  background: linear-gradient(90deg, var(--color-bg-alt) 25%, var(--color-bg) 50%, var(--color-bg-alt) 75%);
  background-size: 200% 100%;
  animation: blog-skeleton-shine 1.5s ease-in-out infinite;
}
@keyframes blog-skeleton-shine {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.blog-empty { text-align: center; padding: var(--space-2xl); color: var(--color-muted); }
.blog-empty .btn { margin-top: var(--space-md); }

/* Pagination */
.blog-pagination {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
}
.blog-pagination a, .blog-pagination span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0 var(--space-md);
  border-radius: var(--radius-md);
  font-weight: 500;
  text-decoration: none;
  color: var(--color-text);
  background: var(--color-bg-alt);
  border: 1px solid transparent;
}
.blog-pagination a:hover { background: var(--color-primary); color: #fff; }
.blog-pagination .current { background: var(--color-primary); color: #fff; }

/* ----- Single post ----- */
.blog-post-page { padding-top: 70px; }
.blog-breadcrumb {
  padding: var(--space-sm) 0;
  font-size: 0.875rem;
}
.blog-breadcrumb .container { padding-left: var(--space-md); padding-right: var(--space-md); }
.blog-breadcrumb ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; align-items: center; gap: 0.25rem; }
.blog-breadcrumb li:not(:last-child)::after { content: '›'; margin-left: 0.25rem; color: var(--color-muted); }
.blog-breadcrumb a { color: var(--color-primary); text-decoration: none; }
.blog-breadcrumb a:hover { text-decoration: underline; }
.blog-breadcrumb li:last-child { color: var(--color-muted); }
.blog-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  width: 0%;
  background: var(--color-primary);
  z-index: 1001;
  transition: width 0.1s ease;
}
.blog-post-hero {
  position: relative;
  min-height: 280px;
  display: flex;
  align-items: flex-end;
  background-color: var(--color-bg-alt);
  background-size: cover;
  background-position: center;
  padding: var(--space-2xl) 0;
}
.blog-post-hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.6), transparent 50%);
  pointer-events: none;
}
.blog-post-hero-inner { position: relative; z-index: 1; color: #fff; }
.blog-post-meta-top { display: flex; gap: var(--space-md); margin-bottom: var(--space-sm); font-size: 0.875rem; opacity: 0.95; }
.blog-post-title { font-size: clamp(1.75rem, 4vw, 2.5rem); margin-bottom: var(--space-sm); line-height: 1.2; }
.blog-post-excerpt { font-size: 1.125rem; opacity: 0.9; margin-bottom: var(--space-md); }
.blog-post-meta-bottom { font-size: 0.875rem; opacity: 0.85; }
.blog-post-body-wrap { padding: var(--space-2xl) 0; }
.blog-post-body-container {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: var(--space-2xl);
  align-items: start;
}
@media (max-width: 768px) {
  .blog-post-body-container { grid-template-columns: 1fr; }
  .blog-toc { position: static !important; }
}

.blog-toc {
  position: sticky;
  top: 90px;
  padding: var(--space-md);
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
}
.blog-toc-title { font-size: 0.875rem; margin-bottom: var(--space-sm); color: var(--color-muted); }
.blog-toc-nav a {
  display: block;
  font-size: 0.875rem;
  padding: var(--space-xs) 0;
  color: var(--color-muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  padding-left: var(--space-sm);
  margin-left: 0;
}
.blog-toc-nav a:hover, .blog-toc-nav a.active { color: var(--color-primary); border-left-color: var(--color-primary); }

/* Prose: max-width, typography */
.prose {
  max-width: 720px;
  line-height: 1.8;
  font-size: 1.0625rem;
}
.prose h2 { font-size: 1.5rem; margin-top: var(--space-2xl); margin-bottom: var(--space-md); }
.prose h3 { font-size: 1.25rem; margin-top: var(--space-xl); margin-bottom: var(--space-sm); }
.prose p { margin-bottom: var(--space-lg); }
.prose ul, .prose ol { margin-bottom: var(--space-lg); padding-left: 1.5em; }
.prose li { margin-bottom: var(--space-xs); }
.prose a { color: var(--color-primary); text-decoration: underline; }
.prose a:hover { opacity: 0.9; }
.prose img { max-width: 100%; height: auto; border-radius: var(--radius-md); }

/* Gallery */
.blog-gallery { padding: var(--space-2xl) 0; }
.blog-gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-md);
}
.blog-gallery-item { margin: 0; }
.blog-gallery-img { width: 100%; height: auto; border-radius: var(--radius-md); cursor: pointer; }

/* Author & share */
.blog-post-footer { padding: var(--space-2xl) 0; border-top: 1px solid var(--border-color, #e5e5e5); }
.blog-author-bio {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}
.blog-author-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.25rem;
}
.blog-author-info h3 { font-size: 1rem; margin-bottom: var(--space-xs); }
.blog-author-info p { font-size: 0.9375rem; color: var(--color-muted); margin: 0; }
.blog-share h3 { font-size: 0.875rem; margin-bottom: var(--space-sm); color: var(--color-muted); }
.blog-share-buttons { display: flex; flex-wrap: wrap; gap: var(--space-sm); }
.blog-share-btn { min-height: 44px; }

.blog-post-navigation {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  margin: var(--space-xl) 0;
}
.blog-post-next { text-align: right; }
.blog-nav-link { font-size: 0.9375rem; }
.blog-nav-link.blog-nav-none { color: var(--color-muted); }
.blog-related h2 { font-size: 1.25rem; margin-bottom: var(--space-lg); }
.blog-related-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: var(--space-lg); }

/* Comments */
.blog-comments { margin-top: var(--space-2xl); padding-top: var(--space-xl); border-top: 1px solid var(--border-color, #e5e5e5); }
.blog-comments h2 { font-size: 1.25rem; margin-bottom: var(--space-lg); }
.blog-comment-form .form-group { margin-bottom: var(--space-md); }
.blog-comment-form label { display: block; margin-bottom: var(--space-xs); font-size: 0.9375rem; }
.blog-comment-form input, .blog-comment-form textarea {
  width: 100%;
  max-width: 400px;
  padding: var(--space-md);
  border: 1px solid var(--border-color, #e5e5e5);
  border-radius: var(--radius-md);
  font-size: 1rem;
  background: var(--color-bg);
  color: var(--color-text);
}
.blog-comment-form .hidden { position: absolute; left: -9999px; }

/* Home widget */
.latest-posts-section { padding: var(--space-2xl) 0; background: var(--color-bg-alt); }
.latest-posts-section .section-title { margin-bottom: var(--space-lg); }
.latest-posts-widget {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}
@media (max-width: 992px) { .latest-posts-widget { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 576px) { .latest-posts-widget { grid-template-columns: 1fr; } }
.latest-posts-placeholder {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-2xl);
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  color: var(--color-muted);
}
.latest-posts-cta { margin-top: var(--space-xl); text-align: center; }
.blog-card.animate-in { animation: blog-fade-in 0.5s ease forwards; }
@keyframes blog-fade-in {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.nav-link-active { font-weight: 600; }