:root {
  --bg: #ffffff;
  --fg: #1f2328;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.65;
}

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

.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 1rem max(1rem, calc((100% - 64rem) / 2));
  border-bottom: 1px solid var(--border);
}

.site-title {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--fg);
}

.site-nav { display: flex; flex-wrap: wrap; gap: 0.85rem; }
.site-nav a { color: var(--muted); font-size: 0.95rem; }
.site-nav a.active, .site-nav a:hover { color: var(--accent); text-decoration: none; }

.site-main {
  max-width: 64rem;
  margin: 0 auto;
  padding: 2rem 1rem 3rem;
}

.prose h2, .prose h3 { margin-top: 1.6em; }
.prose pre {
  overflow-x: auto;
  padding: 1rem;
  background: #f6f8fa;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.88rem;
}
.prose code { font-size: 0.9em; }
.prose blockquote {
  margin-left: 0;
  padding-left: 1rem;
  border-left: 3px solid var(--border);
  color: var(--muted);
}
.prose table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
  font-size: 0.92rem;
  display: block;
  overflow-x: auto;
}
.prose th, .prose td {
  border: 1px solid var(--border);
  padding: 0.4rem 0.6rem;
  text-align: left;
  vertical-align: top;
}
.prose img { max-width: 100%; }

.post-list { display: grid; gap: 0.35rem; }
.post-line {
  display: grid;
  grid-template-columns: 5.5rem 1fr auto;
  gap: 0.8rem;
  align-items: baseline;
  padding: 0.2rem 0;
}
.post-date { color: var(--muted); font-variant-numeric: tabular-nums; }
.post-title { font-weight: 600; }
.post-section { color: var(--muted); font-size: 0.85rem; white-space: nowrap; }

.page-description, .note { color: var(--muted); }
.home-intro { max-width: 55rem; }

.post-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1rem;
  color: var(--muted);
  font-size: 0.92rem;
  margin-bottom: 1.2rem;
}
.post-header h1 { margin-bottom: 0.3rem; }
.lede { color: var(--muted); font-size: 1.02rem; }
.post-body { max-width: 70ch; }
.post-footer {
  margin-top: 2.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: baseline;
}
.companions { margin-top: 2rem; }
.companions h2 { font-size: 1.1rem; }
.tag {
  background: #eef2ff;
  color: #3730a3;
  border-radius: 999px;
  padding: 0.08rem 0.6rem;
  font-size: 0.82rem;
}

.terms-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}
.term {
  background: #f6f8fa;
  border: 1px solid var(--border);
  padding: 0.25rem 0.7rem;
  border-radius: 6px;
}
.term .count { color: var(--muted); }

.site-footer {
  max-width: 64rem;
  margin: 0 auto;
  padding: 1rem;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 600px) {
  .post-line { grid-template-columns: 1fr; gap: 0.1rem; }
  .post-section { display: none; }
}