:root {
  --bg: #0d1117;
  --bg-card: #161b22;
  --bg-hover: #1c2128;
  --border: #30363d;
  --text: #c9d1d9;
  --text-muted: #8b949e;
  --text-heading: #f0f6fc;
  --accent: #58a6ff;
  --accent-hover: #79b8ff;
  --green: #3fb950;
  --radius: 8px;
  --max-width: 880px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
}

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

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.brand-name { font-size: 1.3rem; font-weight: 700; color: var(--text-heading); }
.site-nav { display: flex; gap: 24px; }
.site-nav a { color: var(--text-muted); font-size: 0.95rem; }
.site-nav a:hover { color: var(--text-heading); }

.hero { text-align: center; padding: 60px 0 40px; }
.hero h1 { font-size: 2.5rem; color: var(--text-heading); margin-bottom: 12px; }
.hero-subtitle { color: var(--text-muted); font-size: 1.15rem; max-width: 600px; margin: 0 auto 28px; }
.hero-cta { display: flex; gap: 16px; justify-content: center; }

.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.2s;
  border: 1px solid transparent;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); text-decoration: none; }
.btn-secondary { border-color: var(--border); color: var(--text); }
.btn-secondary:hover { border-color: var(--accent); text-decoration: none; }

.page-header { padding: 40px 0 24px; }
.page-header h1 { font-size: 2rem; color: var(--text-heading); }
.page-subtitle { color: var(--text-muted); margin-top: 8px; }

.post-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  padding: 24px 0;
}
.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.2s;
}
.post-card:hover { border-color: var(--accent); }
.post-card-categories { margin-bottom: 8px; }
.post-card-title { font-size: 1.2rem; margin-bottom: 8px; }
.post-card-title a { color: var(--text-heading); }
.post-card-title a:hover { text-decoration: none; color: var(--accent); }
.post-card-excerpt { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 12px; }
.post-card-meta { font-size: 0.85rem; color: var(--text-muted); }
.separator { margin: 0 6px; }

.category-tag {
  display: inline-block;
  background: rgba(88, 166, 255, 0.1);
  color: var(--accent);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.8rem;
  font-weight: 500;
}
.category-tag:hover { text-decoration: none; background: rgba(88, 166, 255, 0.2); }

.post { padding: 24px 0; }
.breadcrumb { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 16px; }
.breadcrumb a { color: var(--text-muted); }
.breadcrumb span { margin: 0 4px; }

.post-header { margin-bottom: 32px; }
.post-categories { margin-bottom: 8px; }
.post-title { font-size: 2.2rem; color: var(--text-heading); line-height: 1.3; margin-bottom: 12px; }
.post-meta { color: var(--text-muted); font-size: 0.95rem; }
.post-meta time { color: var(--text); }
.updated { font-style: italic; }

.post-feature-image { width: 100%; border-radius: var(--radius); margin-bottom: 32px; }

.post-content { font-size: 1.05rem; line-height: 1.8; }
.post-content h2 { color: var(--text-heading); margin: 32px 0 16px; font-size: 1.5rem; }
.post-content h3 { color: var(--text-heading); margin: 28px 0 12px; font-size: 1.25rem; }
.post-content p { margin-bottom: 16px; }
.post-content ul, .post-content ol { margin: 0 0 16px 24px; }
.post-content li { margin-bottom: 8px; }
.post-content blockquote {
  border-left: 3px solid var(--accent);
  padding: 8px 16px;
  margin: 16px 0;
  color: var(--text-muted);
  background: var(--bg-card);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.post-content code {
  background: var(--bg-card);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: 'SF Mono', Consolas, 'Liberation Mono', monospace;
}
.post-content pre {
  background: #0d1117;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  overflow-x: auto;
  margin: 16px 0;
}
.post-content pre code { background: none; padding: 0; }
.post-content table { border-collapse: collapse; width: 100%; margin: 16px 0; }
.post-content th, .post-content td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
.post-content th { background: var(--bg-card); color: var(--text-heading); }
.post-content img { max-width: 100%; border-radius: var(--radius); margin: 16px 0; }
.post-content a { border-bottom: 1px solid rgba(88, 166, 255, 0.3); }
.post-content a:hover { text-decoration: none; border-bottom-color: var(--accent); }

.post-footer { margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--border); }
.post-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  color: var(--text-muted);
  font-size: 0.85rem;
  background: var(--bg-card);
  padding: 4px 10px;
  border-radius: 12px;
}
.tag:hover { text-decoration: none; color: var(--accent); }

.related-posts { margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--border); }
.related-posts h2 { color: var(--text-heading); font-size: 1.3rem; margin-bottom: 16px; }
.related-posts ul { list-style: none; }
.related-posts li { padding: 8px 0; display: flex; justify-content: space-between; align-items: center; }
.related-posts a { color: var(--text); }
.related-date { color: var(--text-muted); font-size: 0.85rem; }

.cta-box {
  margin-top: 48px;
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
}
.cta-box h2 { color: var(--text-heading); margin-bottom: 8px; }
.cta-box p { color: var(--text-muted); margin-bottom: 20px; }
.cta-box .btn { margin: 0 6px; }

.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 20px;
  padding: 32px 0;
}
.page-link { color: var(--accent); font-weight: 600; }
.page-info { color: var(--text-muted); }

.categories-section { margin-top: 48px; }
.categories-section h2 { color: var(--text-heading); margin-bottom: 16px; }
.category-list { display: flex; flex-wrap: wrap; gap: 16px; }
.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 160px;
}
.category-card:hover { text-decoration: none; border-color: var(--accent); }
.category-name { color: var(--text-heading); font-weight: 600; }
.category-count { color: var(--text-muted); font-size: 0.85rem; margin-top: 4px; }

.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding: 32px 0;
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}
.footer-brand { text-align: center; }
.footer-brand a { color: var(--text-heading); font-weight: 700; font-size: 1.1rem; }
.footer-brand p { color: var(--text-muted); font-size: 0.9rem; margin-top: 4px; }
.footer-nav { display: flex; gap: 20px; }
.footer-nav a { color: var(--text-muted); font-size: 0.9rem; }
.footer-legal { display: flex; gap: 16px; }
.footer-legal a { color: var(--text-muted); font-size: 0.85rem; }
.footer-copy { color: var(--text-muted); font-size: 0.85rem; }

.error-page { text-align: center; padding: 80px 0; }
.error-page h1 { font-size: 4rem; color: var(--text-heading); }
.error-page p { color: var(--text-muted); margin: 16px 0 24px; }

@media (max-width: 600px) {
  .header-inner { flex-direction: column; gap: 12px; }
  .site-nav { flex-wrap: wrap; justify-content: center; gap: 16px; }
  .hero h1 { font-size: 1.8rem; }
  .post-title { font-size: 1.6rem; }
  .post-grid { grid-template-columns: 1fr; }
  .hero-cta { flex-direction: column; align-items: center; }
}