/* ============================================
   NCSE Blog Theme — Aligned with ncse.tw
   Primary: #3d7fb8 scale | Font: Noto Sans TC
   ============================================ */

:root {
  --primary-50:  #f0f7fe;
  --primary-200: #a2cbf1;
  --primary-300: #75b4eb;
  --primary-500: #3d7fb8;
  --primary-600: #2d6090;
  --primary-700: #234d73;
  --primary-800: #1a3a56;
  --primary-900: #12273d;

  --gray-50:  #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;

  --font-sans: 'Noto Sans TC', ui-sans-serif, system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'Courier New', monospace;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);

  --header-height: 64px;
  --container-max: 1200px;
  --content-max: 760px;
}

/* ============ RESET ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; overflow-x: hidden; }
body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--gray-800);
  background: #fff;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }

/* ============ CONTAINER ============ */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}
@media (min-width: 768px) { .container { padding: 0 2rem; } }

/* ============ HEADER ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-height);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--gray-200);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 2rem;
  height: var(--header-height);
}
.site-logo img {
  height: 36px;
  width: auto;
  object-fit: contain;
}
.logo-text {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--primary-800);
  letter-spacing: -0.02em;
}
.site-nav {
  display: none;
  gap: 0.25rem;
  margin-left: auto;
}
@media (min-width: 768px) { .site-nav { display: flex; } }
.nav-link {
  padding: 0.5rem 0.75rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-600);
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}
.nav-link:hover, .nav-link.active {
  color: var(--primary-600);
  background: var(--primary-50);
}
.btn-cta {
  display: none;
  margin-left: auto;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: #fff;
  background: var(--primary-600);
  border-radius: var(--radius-sm);
  transition: background 0.15s;
}
.btn-cta:hover { background: var(--primary-700); }
@media (min-width: 768px) { .btn-cta { display: block; } }
@media (min-width: 768px) { .btn-cta { margin-left: 0; } }
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-left: auto;
  padding: 0.5rem;
  background: none;
  border: none;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--gray-700);
  border-radius: 2px;
  transition: all 0.2s;
}
@media (min-width: 768px) { .nav-toggle { display: none; } }

/* Mobile nav open */
.site-header.nav-open .site-nav {
  display: flex;
  flex-direction: column;
  position: absolute;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: #fff;
  border-bottom: 1px solid var(--gray-200);
  padding: 1rem 1.5rem;
  gap: 0.25rem;
}

/* ============ HERO ============ */
.hero {
  background: linear-gradient(135deg, var(--primary-900) 0%, var(--primary-700) 60%, var(--primary-500) 100%);
  padding: 5rem 0 4rem;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
}
.hero-inner {
  position: relative;
  max-width: 640px;
}
.hero-badge {
  display: inline-block;
  padding: 0.375rem 0.875rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--primary-200);
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 100px;
  margin-bottom: 1.5rem;
}
.hero h1 {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.15;
  color: #fff;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
}
.hero-accent { color: var(--primary-300); }
.hero p {
  font-size: 1.125rem;
  color: rgba(255,255,255,0.8);
  margin-bottom: 2rem;
  max-width: 520px;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn-primary {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--primary-900);
  background: #fff;
  border-radius: var(--radius-sm);
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-ghost {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: rgba(255,255,255,0.9);
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: var(--radius-sm);
  transition: background 0.15s, border-color 0.15s;
}
.btn-ghost:hover { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.5); }

/* ============ POSTS SECTION ============ */
.posts-section { padding: 4rem 0; }

/* Featured post */
.post-featured {
  background: var(--primary-50);
  border: 1px solid var(--primary-200);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  margin-bottom: 2.5rem;
  transition: box-shadow 0.2s;
}
.post-featured:hover { box-shadow: var(--shadow-md); }
.post-featured-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}
.post-featured-meta time { font-size: 0.875rem; color: var(--gray-500); }
.post-featured-title {
  font-size: clamp(1.375rem, 3vw, 1.875rem);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 0.875rem;
}
.post-featured-title a { color: var(--primary-900); transition: color 0.15s; }
.post-featured-title a:hover { color: var(--primary-600); }
.post-featured-excerpt { color: var(--gray-600); margin-bottom: 1.25rem; font-size: 1rem; }
.post-read-more { font-size: 0.9rem; font-weight: 600; color: var(--primary-600); transition: color 0.15s; }
.post-read-more:hover { color: var(--primary-800); }

/* Posts grid */
.posts-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin-bottom: 3rem;
}
@media (min-width: 640px) { .posts-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .posts-grid { grid-template-columns: repeat(3, 1fr); } }

.post-card {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}
.post-card:hover {
  border-color: var(--primary-300);
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
}
.post-card-meta { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 0.75rem; }
.post-card-meta time { font-size: 0.8rem; color: var(--gray-400); }
.post-card-title { font-size: 1rem; font-weight: 600; line-height: 1.4; margin-bottom: 0.5rem; }
.post-card-title a { color: var(--gray-800); transition: color 0.15s; }
.post-card-title a:hover { color: var(--primary-600); }
.post-card-excerpt { font-size: 0.875rem; color: var(--gray-500); line-height: 1.6; }

/* Tag badge */
.tag-badge {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary-700);
  background: var(--primary-50);
  border: 1px solid var(--primary-200);
  border-radius: 100px;
  transition: background 0.15s;
}
.tag-badge:hover { background: var(--primary-200); }
.tag-badge--small { padding: 0.125rem 0.5rem; font-size: 0.7rem; }

/* Pagination */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 2rem 0;
}
.pagination-btn {
  padding: 0.5rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary-600);
  border: 1px solid var(--primary-300);
  border-radius: var(--radius-sm);
  transition: all 0.15s;
}
.pagination-btn:hover { background: var(--primary-50); }
.pagination-info { font-size: 0.875rem; color: var(--gray-500); }

/* ============ POST ARTICLE ============ */
.post-article { padding: 3rem 0 5rem; }
.post-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}
@media (min-width: 1024px) {
  .post-layout { grid-template-columns: minmax(0, 1fr) 260px; align-items: start; }
}

.post-header { margin-bottom: 2.5rem; padding-bottom: 2rem; border-bottom: 1px solid var(--gray-200); }
.post-header-meta { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 1rem; flex-wrap: wrap; }
.post-header-meta time { font-size: 0.875rem; color: var(--gray-500); }
.post-title {
  font-size: clamp(1.625rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.03em;
  color: var(--primary-900);
  margin-bottom: 0.875rem;
}
.post-subtitle { font-size: 1.125rem; color: var(--gray-500); line-height: 1.6; }

/* Post body typography */
.post-body { font-size: 1.0625rem; line-height: 1.85; color: var(--gray-700); }
.post-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-900);
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary-200);
  letter-spacing: -0.02em;
}
.post-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-800);
  margin: 2rem 0 0.75rem;
}
.post-body h4 { font-size: 1.0625rem; font-weight: 700; color: var(--gray-800); margin: 1.5rem 0 0.5rem; }
.post-body p { margin-bottom: 1.5rem; }
.post-body a { color: var(--primary-600); text-decoration: underline; text-underline-offset: 3px; }
.post-body a:hover { color: var(--primary-800); }
.post-body ul, .post-body ol { padding-left: 1.5rem; margin-bottom: 1.5rem; }
.post-body li { margin-bottom: 0.5rem; }
.post-body blockquote {
  border-left: 4px solid var(--primary-500);
  padding: 1rem 1.5rem;
  background: var(--primary-50);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0;
  color: var(--gray-600);
  font-style: italic;
}
.post-body img {
  border-radius: var(--radius-md);
  margin: 2rem auto;
  box-shadow: var(--shadow-md);
}
.post-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9375rem;
  overflow-x: auto;
  display: block;
}
.post-body th {
  background: var(--primary-900);
  color: #fff;
  padding: 0.75rem 1rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.875rem;
}
.post-body td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--gray-200); vertical-align: top; }
.post-body tr:last-child td { border-bottom: none; }
.post-body tr:nth-child(even) td { background: var(--gray-50); }

/* Code blocks */
.post-body code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--gray-100);
  color: var(--primary-800);
  padding: 0.15em 0.45em;
  border-radius: 4px;
}
.post-body pre {
  background: var(--primary-900);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-size: 0.875rem;
  line-height: 1.7;
}
.post-body pre code {
  background: none;
  color: #e2e8f0;
  padding: 0;
  font-size: 1em;
}

/* Post tags */
.post-tags { display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; margin-top: 2.5rem; padding-top: 1.5rem; border-top: 1px solid var(--gray-200); font-size: 0.875rem; color: var(--gray-500); }

/* Post CTA */
.post-cta {
  margin: 3rem 0;
  background: linear-gradient(135deg, var(--primary-900), var(--primary-700));
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.post-cta-inner { padding: 2.5rem; }
.post-cta h3 { font-size: 1.25rem; font-weight: 700; color: #fff; margin-bottom: 0.625rem; }
.post-cta p { color: rgba(255,255,255,0.75); margin-bottom: 1.5rem; font-size: 0.9375rem; }

/* Post nav */
.post-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 3rem; }
.post-nav-item {
  padding: 1.25rem;
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  transition: border-color 0.15s, background 0.15s;
}
.post-nav-item:hover { border-color: var(--primary-300); background: var(--primary-50); }
.post-nav-next { text-align: right; }
.post-nav-label { display: block; font-size: 0.75rem; color: var(--gray-400); margin-bottom: 0.375rem; text-transform: uppercase; letter-spacing: 0.05em; }
.post-nav-title { font-size: 0.875rem; font-weight: 600; color: var(--gray-700); line-height: 1.4; }

/* ============ SIDEBAR / TOC ============ */
.post-sidebar { display: none; }
@media (min-width: 1024px) { .post-sidebar { display: block; } }
.toc-wrapper {
  position: sticky;
  top: calc(var(--header-height) + 1.5rem);
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  max-height: calc(100vh - var(--header-height) - 3rem);
  overflow-y: auto;
}
.toc-title { font-size: 0.8rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--gray-400); margin-bottom: 0.875rem; }
.toc-content ol { list-style: none; padding: 0; }
.toc-content li { margin-bottom: 0.375rem; }
.toc-content a {
  font-size: 0.875rem;
  color: var(--gray-600);
  transition: color 0.15s;
  line-height: 1.5;
  display: block;
}
.toc-content a:hover, .toc-content a.active { color: var(--primary-600); }
.toc-content ol ol { padding-left: 1rem; margin-top: 0.25rem; }
.toc-content ol ol a { font-size: 0.8125rem; color: var(--gray-400); }

/* ============ PAGE HEADER ============ */
.page-header {
  background: var(--primary-900);
  padding: 3rem 0;
  margin-bottom: 3rem;
}
.page-header h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.03em;
  margin-bottom: 0.375rem;
}
.page-header p { color: rgba(255,255,255,0.6); font-size: 0.9375rem; }

/* ============ ARCHIVE ============ */
.archive-list { margin-bottom: 3rem; }
.archive-year {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-900);
  padding: 2rem 0 1rem;
  letter-spacing: -0.02em;
}
.archive-item {
  display: flex;
  align-items: baseline;
  gap: 1.25rem;
  padding: 0.875rem 0;
  border-bottom: 1px solid var(--gray-100);
  flex-wrap: wrap;
}
.archive-item time { font-size: 0.8125rem; color: var(--gray-400); font-variant-numeric: tabular-nums; flex-shrink: 0; font-family: var(--font-mono); }
.archive-title { font-size: 0.9375rem; font-weight: 500; color: var(--gray-700); transition: color 0.15s; flex: 1; min-width: 200px; }
.archive-title:hover { color: var(--primary-600); }
.archive-tags { display: flex; gap: 0.375rem; flex-wrap: wrap; }

/* ============ PAGE BODY ============ */
.page-body {
  max-width: var(--content-max);
  margin: 0 auto 5rem;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--gray-700);
}
.page-body h2 { font-size: 1.5rem; font-weight: 700; color: var(--primary-900); margin: 2rem 0 1rem; }
.page-body p { margin-bottom: 1.25rem; }

/* ============ FOOTER ============ */
.site-footer {
  background: var(--primary-900);
  color: rgba(255,255,255,0.7);
  padding: 3.5rem 0 0;
  margin-top: 5rem;
}
.footer-inner { display: grid; grid-template-columns: 1fr; gap: 2.5rem; margin-bottom: 3rem; }
@media (min-width: 768px) { .footer-inner { grid-template-columns: 1fr auto; } }
.footer-logo { font-size: 1.125rem; font-weight: 700; color: #fff; display: block; margin-bottom: 0.75rem; }
.footer-desc { font-size: 0.875rem; color: rgba(255,255,255,0.5); max-width: 300px; }
.footer-links { display: flex; gap: 3rem; flex-wrap: wrap; }
.footer-col { display: flex; flex-direction: column; gap: 0.625rem; }
.footer-col h4 { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.4); margin-bottom: 0.375rem; }
.footer-col a { font-size: 0.875rem; color: rgba(255,255,255,0.6); transition: color 0.15s; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 1.5rem 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-bottom p { font-size: 0.8125rem; color: rgba(255,255,255,0.4); }
.rss-link { font-size: 0.8125rem; color: rgba(255,255,255,0.4); transition: color 0.15s; }
.rss-link:hover { color: rgba(255,255,255,0.8); }

/* ============ EMPTY STATE ============ */
.empty-state { text-align: center; padding: 5rem 0; color: var(--gray-400); }

/* ============ SCROLLBAR ============ */
.toc-wrapper::-webkit-scrollbar { width: 4px; }
.toc-wrapper::-webkit-scrollbar-track { background: transparent; }
.toc-wrapper::-webkit-scrollbar-thumb { background: var(--gray-300); border-radius: 2px; }

/* ============ FOOTER OVERRIDE ============ */
.site-footer {
  background: #111827;
  color: #d1d5db;
  padding: 3rem 0 0;
  margin-top: 5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding-bottom: 2rem;
}
@media (min-width: 768px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr; gap: 2rem; }
}
.footer-brand-title { font-size: 1.25rem; font-weight: 700; color: #fff; margin-bottom: 1rem; }
.footer-brand-desc { font-size: 0.875rem; color: #d1d5db; margin-bottom: 1rem; line-height: 1.6; }
.footer-brand-links { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; font-size: 0.875rem; }
.footer-brand-links a { color: #d1d5db; transition: color 0.15s; }
.footer-brand-links a:hover { color: #fff; }
.footer-brand-links span { color: #6b7280; }
.footer-col h4 { font-size: 0.9375rem; font-weight: 600; color: #fff; margin-bottom: 1rem; }
.footer-col ul { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 0.5rem; }
.footer-col ul a { font-size: 0.875rem; color: #d1d5db; transition: color 0.15s; }
.footer-col ul a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid #1f2937;
  padding: 2rem 0;
  text-align: center;
}
.footer-bottom p { font-size: 0.875rem; color: #9ca3af; }
.footer-bottom-sub { margin-top: 0.5rem; display: flex; align-items: center; justify-content: center; gap: 0.5rem; flex-wrap: wrap; }
.footer-bottom-sub a { color: #d1d5db; text-decoration: underline; text-underline-offset: 2px; transition: color 0.15s; }
.footer-bottom-sub a:hover { color: #fff; }
.footer-bottom-sub span { color: #4b5563; }