/* ══════════════════════════════════════════════════
   THEME TOKENS  —  Light & Dark
   ══════════════════════════════════════════════════ */
:root {
  --bg:            #ffffff;
  --bg-secondary:  #f7f7f5;
  --bg-sidebar:    #f4f4f0;
  --bg-code:       #f0f0ec;
  --bg-series:     #f0fdf4;

  --text:          #1c1c1e;
  --text-secondary:#4b4b4f;
  --text-muted:    #8a8a8e;
  --text-link:     #1a56c4;
  --text-link-hover:#0f3d8f;

  --border:        #e4e4e0;
  --border-strong: #c8c8c4;

  --accent:        #1a56c4;
  --accent-light:  #dbeafe;
  --series-green:  #16a34a;
  --series-border: #22c55e;
  --series-bg:     #f0fdf4;

  --tag-bg:        #eff6ff;
  --tag-text:      #1e40af;
  --tag-border:    #bfdbfe;

  --header-bg:     rgba(255,255,255,0.92);
  --shadow-sm:     0 1px 3px rgba(0,0,0,.08);
  --shadow-md:     0 4px 12px rgba(0,0,0,.10);

  --font-body:     'Lora', Georgia, 'Times New Roman', Times, serif;
  --font-ui:       'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:     'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;

  --header-h:      60px;
  --sidebar-w:     280px;
  --content-max:   720px;
  --page-max:      1160px;
  --radius:        6px;
  --radius-lg:     10px;
  --transition:    0.18s ease;
}

[data-theme="dark"] {
  --bg:            #111113;
  --bg-secondary:  #18181b;
  --bg-sidebar:    #141416;
  --bg-code:       #1e1e22;
  --bg-series:     #0c1f12;

  --text:          #e8e8ea;
  --text-secondary:#a8a8ad;
  --text-muted:    #606065;
  --text-link:     #60a5fa;
  --text-link-hover:#93c5fd;

  --border:        #2a2a2e;
  --border-strong: #3f3f44;

  --accent:        #60a5fa;
  --accent-light:  #1e3a5f;
  --series-green:  #4ade80;
  --series-border: #22c55e;
  --series-bg:     #0a1f0e;

  --tag-bg:        #1e3356;
  --tag-text:      #93c5fd;
  --tag-border:    #2d4f8a;

  --header-bg:     rgba(17,17,19,0.92);
  --shadow-sm:     0 1px 3px rgba(0,0,0,.4);
  --shadow-md:     0 4px 12px rgba(0,0,0,.5);
}

/* ══════════════════════════════════════════════════
   RESET & BASE
   ══════════════════════════════════════════════════ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 17px; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

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

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

/* ══════════════════════════════════════════════════
   HEADER
   ══════════════════════════════════════════════════ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  height: var(--header-h);
}

.header-inner {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.site-title {
  font-family: var(--font-ui);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
  letter-spacing: -0.02em;
}
.site-title:hover { color: var(--accent); text-decoration: none; }

.site-nav {
  display: flex;
  gap: 0.25rem;
  margin-left: 0.5rem;
  flex: 1;
}

.nav-link {
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius);
  text-decoration: none;
  transition: background var(--transition), color var(--transition);
}
.nav-link:hover { background: var(--bg-secondary); color: var(--text); text-decoration: none; }
.nav-link.active { color: var(--accent); background: var(--accent-light); }

.header-controls {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: auto;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: var(--radius);
  transition: background var(--transition), color var(--transition);
}
.icon-btn:hover { background: var(--bg-secondary); color: var(--text); }

/* Sun/moon icon swap */
[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"]  .icon-sun  { display: none; }

.mobile-menu-btn { display: none; }

.mobile-nav {
  display: none;
  flex-direction: column;
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 0.75rem 1.5rem 1rem;
}
.mobile-nav.open { display: flex; }
.mobile-nav-link {
  font-family: var(--font-ui);
  font-size: 0.95rem;
  color: var(--text-secondary);
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
}
.mobile-nav-link:last-child { border-bottom: none; }

/* ══════════════════════════════════════════════════
   PAGE LAYOUT  (2-column: content + sidebar)
   ══════════════════════════════════════════════════ */
.page-wrapper {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3rem;
  display: grid;
  grid-template-columns: 1fr var(--sidebar-w);
  gap: 3rem;
  align-items: start;
}

.main-content {
  min-width: 0; /* prevents overflow in grid */
  max-width: var(--content-max);
}

/* ══════════════════════════════════════════════════
   HOME PAGE
   ══════════════════════════════════════════════════ */
.home-hero {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 2px solid var(--border);
}
.home-title {
  font-family: var(--font-ui);
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 0.4rem;
}
.home-tagline {
  font-size: 1rem;
  color: var(--text-muted);
  font-style: italic;
}

/* Active filter bar */
.active-filter-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-ui);
  font-size: 0.875rem;
  color: var(--text-secondary);
  background: var(--accent-light);
  border: 1px solid var(--tag-border);
  border-radius: var(--radius);
  padding: 0.4rem 0.75rem;
  margin-bottom: 1.5rem;
}
.active-filter-bar strong { color: var(--accent); }
#clear-filter {
  margin-left: auto;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.8rem;
  padding: 0.1rem 0.3rem;
  border-radius: 4px;
  font-family: var(--font-ui);
}
#clear-filter:hover { background: var(--border); color: var(--text); }

/* ══════════════════════════════════════════════════
   POST CARD
   ══════════════════════════════════════════════════ */
.post-card {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
}
.post-card:last-child { border-bottom: none; }

.post-card-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.35rem;
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
}
.meta-sep { color: var(--border-strong); }

.series-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.78rem;
  color: var(--series-green);
  text-decoration: none;
  font-weight: 500;
}
.series-badge:hover { color: var(--series-green); text-decoration: underline; }
.series-part-badge {
  background: var(--series-bg);
  border: 1px solid var(--series-border);
  border-radius: 4px;
  padding: 0 5px;
  font-size: 0.72rem;
}

.post-card-title {
  font-family: var(--font-ui);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.35;
  margin-bottom: 0.5rem;
}
.post-card-title a { color: var(--text); text-decoration: none; }
.post-card-title a:hover { color: var(--accent); }

.post-card-excerpt {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 0.75rem;
}

.post-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.75rem;
}

.read-more-link {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
}
.read-more-link:hover { text-decoration: underline; }

/* ══════════════════════════════════════════════════
   TAG CHIPS
   ══════════════════════════════════════════════════ */
.tag-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--tag-text);
  background: var(--tag-bg);
  border: 1px solid var(--tag-border);
  border-radius: 20px;
  padding: 2px 10px;
  text-decoration: none;
  transition: background var(--transition), border-color var(--transition);
  white-space: nowrap;
}
.tag-chip:hover {
  background: var(--accent-light);
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}
.tag-chip.small { font-size: 0.72rem; padding: 1px 8px; }
.tag-count {
  font-size: 0.68rem;
  color: var(--text-muted);
  margin-left: 2px;
}

/* ══════════════════════════════════════════════════
   PAGINATION
   ══════════════════════════════════════════════════ */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.pagination-btn {
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: background var(--transition);
}
.pagination-btn:hover { background: var(--bg-secondary); text-decoration: none; }
.pagination-btn.disabled { color: var(--text-muted); pointer-events: none; }
.pagination-info { font-family: var(--font-ui); font-size: 0.85rem; color: var(--text-muted); }

/* ══════════════════════════════════════════════════
   POST PAGE
   ══════════════════════════════════════════════════ */
.back-link {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--text-muted);
  text-decoration: none;
  margin-bottom: 1.5rem;
}
.back-link:hover { color: var(--accent); }

.post-header { margin-bottom: 2rem; }

.post-title {
  font-family: var(--font-ui);
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.25;
  margin-bottom: 0.75rem;
}

.post-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.35rem;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.post-header-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.post-hero-image {
  margin: 1.5rem 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.post-hero-image img { width: 100%; object-fit: cover; }
.post-hero-image figcaption {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 0.5rem;
  font-style: italic;
}

/* ── Post Content Typography ── */
.post-content {
  font-size: 1rem;
  line-height: 1.85;
}
.post-content h1,
.post-content h2,
.post-content h3,
.post-content h4 {
  font-family: var(--font-ui);
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
  margin: 2rem 0 0.75rem;
  line-height: 1.3;
}
.post-content h1 { font-size: 1.75rem; }
.post-content h2 { font-size: 1.4rem; border-bottom: 1px solid var(--border); padding-bottom: 0.35rem; }
.post-content h3 { font-size: 1.15rem; }
.post-content h4 { font-size: 1rem; }

.post-content p { margin-bottom: 1.25rem; }

.post-content a { color: var(--text-link); }
.post-content a:hover { color: var(--text-link-hover); }

.post-content ul,
.post-content ol {
  padding-left: 1.6rem;
  margin-bottom: 1.25rem;
}
.post-content li { margin-bottom: 0.4rem; }

.post-content blockquote {
  border-left: 4px solid var(--accent);
  margin: 1.5rem 0;
  padding: 0.75rem 1.25rem;
  background: var(--bg-secondary);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text-secondary);
  font-style: italic;
}

.post-content pre {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  overflow-x: auto;
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.65;
}
.post-content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-code);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--border);
}
.post-content pre code {
  background: none;
  padding: 0;
  border: none;
  font-size: 1em;
}

.post-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.25rem;
  font-family: var(--font-ui);
  font-size: 0.9rem;
}
.post-content th {
  background: var(--bg-secondary);
  font-weight: 600;
  text-align: left;
  padding: 0.6rem 0.9rem;
  border: 1px solid var(--border);
}
.post-content td {
  padding: 0.5rem 0.9rem;
  border: 1px solid var(--border);
}
.post-content tr:nth-child(even) { background: var(--bg-secondary); }

.post-content img {
  border-radius: var(--radius);
  margin: 1.5rem auto;
  box-shadow: var(--shadow-md);
}

.post-content hr {
  border: none;
  border-top: 2px solid var(--border);
  margin: 2.5rem 0;
}

/* ── Prev / Next navigation ── */
.post-adjacent {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.adjacent-link {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-family: var(--font-ui);
  text-decoration: none;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.adjacent-link:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
  text-decoration: none;
}
.adjacent-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.adjacent-title {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.4;
}
.adjacent-next {
  text-align: right;
}

/* ══════════════════════════════════════════════════
   SERIES NAVIGATION BOX
   ══════════════════════════════════════════════════ */
.series-nav-box {
  background: var(--series-bg);
  border: 1px solid var(--series-border);
  border-left: 4px solid var(--series-border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.4rem;
  margin: 2rem 0;
}

.series-nav-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}
.series-nav-emoji {
  font-size: 1.75rem;
  line-height: 1;
  flex-shrink: 0;
}
.series-nav-label {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--series-green);
  margin-bottom: 0.2rem;
}
.series-nav-title {
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.series-nav-title a { color: var(--text); text-decoration: none; }
.series-nav-title a:hover { color: var(--series-green); }

.series-nav-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-style: italic;
}

.series-nav-list {
  list-style: none;
  padding: 0;
  margin-bottom: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.series-nav-list li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-ui);
  font-size: 0.88rem;
  padding: 0.35rem 0.6rem;
  border-radius: var(--radius);
}
.series-nav-list li.series-nav-current {
  background: rgba(34,197,94,0.12);
  font-weight: 600;
}
.series-part-indicator {
  min-width: 22px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--series-green);
  font-weight: 700;
}
.series-nav-post-title { flex: 1; }
.series-nav-post-title:not(a) { color: var(--text); }
.series-nav-badge {
  font-size: 0.68rem;
  font-weight: 600;
  background: var(--series-green);
  color: #fff;
  padding: 1px 6px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.series-nav-footer {
  display: flex;
  justify-content: space-between;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}
.series-nav-arrow {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--series-green);
  text-decoration: none;
  max-width: 46%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.series-nav-arrow:hover { text-decoration: underline; }
.series-nav-arrow--next { text-align: right; }

/* ══════════════════════════════════════════════════
   SIDEBAR
   ══════════════════════════════════════════════════ */
.sidebar-wrapper {
  position: sticky;
  top: calc(var(--header-h) + 1.5rem);
  max-height: calc(100vh - var(--header-h) - 3rem);
  overflow-y: auto;
  padding-right: 4px;
  /* custom scrollbar */
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
.sidebar-wrapper::-webkit-scrollbar { width: 4px; }
.sidebar-wrapper::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.sidebar-section {
  margin-bottom: 1.75rem;
  padding-bottom: 1.75rem;
  border-bottom: 1px solid var(--border);
}
.sidebar-section:last-child { border-bottom: none; }

.sidebar-heading {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.85rem;
}

/* Series list */
.sidebar-series-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.sidebar-series-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-ui);
  font-size: 0.85rem;
}
.sidebar-series-list a {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-secondary);
  text-decoration: none;
  flex: 1;
  min-width: 0;
}
.sidebar-series-list a:hover { color: var(--accent); text-decoration: underline; }
.series-emoji { font-size: 0.9rem; flex-shrink: 0; }
.series-title-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.series-count {
  font-size: 0.72rem;
  font-family: var(--font-ui);
  background: var(--bg-secondary);
  color: var(--text-muted);
  border-radius: 20px;
  padding: 1px 7px;
  border: 1px solid var(--border);
  flex-shrink: 0;
  margin-left: 0.4rem;
}

/* Tag cloud */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.sidebar-tag .tag-count { display: inline; }

/* Recent posts */
.sidebar-recent-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.sidebar-recent-list li {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
}
.sidebar-recent-list a {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-decoration: none;
  line-height: 1.4;
}
.sidebar-recent-list a:hover { color: var(--accent); }
.sidebar-date {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* Archive list */
.sidebar-archive-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}
.sidebar-archive-list a {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.2rem 0;
}
.sidebar-archive-list a:hover { color: var(--accent); }
.archive-count {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-family: var(--font-ui);
}

/* ══════════════════════════════════════════════════
   PAGE LAYOUTS  (Tags, Archive, Series, About)
   ══════════════════════════════════════════════════ */
.page-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--border);
}
.page-title {
  font-family: var(--font-ui);
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}
.page-description {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
  font-style: italic;
}
.page-content { line-height: 1.75; }
.page-content h1, .page-content h2, .page-content h3 {
  font-family: var(--font-ui);
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
}

/* Tags page */
.tags-section { margin-bottom: 2.5rem; }
.tag-section-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}
.tag-section-title {
  font-family: var(--font-ui);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
}
.tag-post-count {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 2px 8px;
  border-radius: 20px;
  border: 1px solid var(--border);
}
.tag-post-list { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.tag-post-list li {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  font-family: var(--font-ui);
  font-size: 0.9rem;
}
.tag-post-list time { color: var(--text-muted); font-size: 0.8rem; flex-shrink: 0; }
.tag-post-list a { color: var(--text-secondary); text-decoration: none; }
.tag-post-list a:hover { color: var(--accent); }

/* Tags filter bar */
.tags-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 2rem;
  padding: 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

/* Archive page */
.archive-year { margin-bottom: 2.5rem; }
.archive-year-header {
  font-family: var(--font-ui);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}
.archive-month { margin-bottom: 1.25rem; }
.archive-month-label {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}
.archive-post-list { list-style: none; }
.archive-post-list li {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding: 0.3rem 0;
  border-bottom: 1px dotted var(--border);
}
.archive-post-list li:last-child { border-bottom: none; }
.archive-post-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  flex-shrink: 0;
}
.archive-post-list a { font-family: var(--font-ui); font-size: 0.9rem; color: var(--text-secondary); text-decoration: none; }
.archive-post-list a:hover { color: var(--accent); }

/* Series page */
.series-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 2rem;
}
.series-card-header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 0.75rem;
}
.series-card-emoji { font-size: 2rem; line-height: 1; flex-shrink: 0; }
.series-card-title {
  font-family: var(--font-ui);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}
.series-card-tags { display: flex; flex-wrap: wrap; gap: 0.3rem; }
.series-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-style: italic;
}
.series-post-ol {
  padding-left: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.series-post-ol li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-ui);
  font-size: 0.875rem;
  padding: 0.3rem 0;
  border-bottom: 1px dotted var(--border);
}
.series-post-ol li:last-child { border-bottom: none; }
.series-post-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--series-green);
  font-weight: 700;
  min-width: 1.2rem;
}
.series-post-ol a { color: var(--text-secondary); text-decoration: none; flex: 1; }
.series-post-ol a:hover { color: var(--accent); }
.series-post-date { font-size: 0.75rem; color: var(--text-muted); flex-shrink: 0; }

/* ══════════════════════════════════════════════════
   SEARCH MODAL
   ══════════════════════════════════════════════════ */
.search-modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 10vh;
}
.search-modal[hidden] { display: none; }

.search-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.45);
  backdrop-filter: blur(4px);
}

.search-panel {
  position: relative;
  z-index: 1;
  width: min(640px, 92vw);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.search-input-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
}

#search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-family: var(--font-ui);
  font-size: 1rem;
  color: var(--text);
}
#search-input::placeholder { color: var(--text-muted); }

.search-close-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: var(--font-ui);
}
.search-close-btn:hover { background: var(--bg-secondary); color: var(--text); }

.search-results {
  max-height: 420px;
  overflow-y: auto;
  padding: 0.5rem 0;
}
.search-result-item {
  display: block;
  padding: 0.75rem 1.25rem;
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}
.search-result-item:last-child { border-bottom: none; }
.search-result-item:hover { background: var(--bg-secondary); }
.search-result-title {
  font-family: var(--font-ui);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.2rem;
}
.search-result-meta {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  color: var(--text-muted);
}
.search-empty, .search-prompt {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  color: var(--text-muted);
  text-align: center;
  padding: 2rem 1rem;
}
.search-hint {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-align: center;
  padding: 0.5rem 1rem;
  border-top: 1px solid var(--border);
}
kbd {
  font-family: var(--font-mono);
  font-size: 0.7em;
  padding: 1px 5px;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
}

/* ══════════════════════════════════════════════════
   SYNTAX HIGHLIGHTING  (Rouge)
   ══════════════════════════════════════════════════ */
.highlight .hll { background-color: #ffffcc }
.highlight .c   { color:#6a737d; font-style:italic }
.highlight .k   { color:#d73a49; font-weight:bold }
.highlight .n   { color: var(--text) }
.highlight .o   { color:#6f42c1 }
.highlight .s   { color:#032f62 }
.highlight .nb  { color:#005cc5 }
.highlight .nc  { color:#6f42c1 }
.highlight .nf  { color:#6f42c1 }
.highlight .mi  { color:#005cc5 }
[data-theme="dark"] .highlight .s  { color:#9ecbff }
[data-theme="dark"] .highlight .k  { color:#f97583 }
[data-theme="dark"] .highlight .nb { color:#79b8ff }
[data-theme="dark"] .highlight .nc,
[data-theme="dark"] .highlight .nf { color:#b392f0 }
[data-theme="dark"] .highlight .mi { color:#79b8ff }

/* ══════════════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════════════ */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem;
}
.footer-inner {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--text-muted);
}
.footer-left { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.footer-left a { color: var(--text-muted); }
.footer-left a:hover { color: var(--accent); }
.footer-right { display: flex; align-items: center; gap: 0.75rem; }
.footer-right a { color: var(--text-muted); display: flex; }
.footer-right a:hover { color: var(--accent); }

/* ══════════════════════════════════════════════════
   RESPONSIVE
   ══════════════════════════════════════════════════ */
@media (max-width: 900px) {
  .page-wrapper {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .sidebar-wrapper {
    position: static;
    max-height: none;
    border-top: 2px solid var(--border);
    padding-top: 2rem;
  }
  .main-content { max-width: 100%; }
}

@media (max-width: 640px) {
  :root { --header-h: 54px; }
  html { font-size: 16px; }

  .site-nav { display: none; }
  .mobile-menu-btn { display: flex; }

  .page-wrapper { padding: 1.5rem 1rem 2rem; }

  .post-title { font-size: 1.6rem; }
  .home-title { font-size: 1.5rem; }

  .post-adjacent { grid-template-columns: 1fr; }
  .adjacent-next { text-align: left; }

  .series-nav-footer { flex-direction: column; gap: 0.5rem; }
  .series-nav-arrow { max-width: 100%; }
}

@media (max-width: 400px) {
  .header-inner { padding: 0 0.75rem; }
}

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