:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --text: #1f2328;
  --muted: #6b7280;
  --accent: #6c5ce7;
  --accent-soft: #efecff;
  --border: #e8eaed;
  --code-bg: #f4f5f7;
  --maxw: 820px;
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg-soft);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
}
.brand:hover { text-decoration: none; color: var(--accent); }
.nav { display: flex; gap: 22px; }
.nav a {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 500;
}
.nav a:hover, .nav a.active { color: var(--accent); text-decoration: none; }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, #efecff 0%, #f6f7f9 60%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  margin: 32px 0 8px;
  text-align: center;
}
.hero__title { margin: 0 0 10px; font-size: 1.9rem; }
.hero__subtitle { margin: 0; color: var(--muted); }

/* ---------- Sections ---------- */
main { padding-bottom: 40px; }
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin: 36px 0 16px;
}
.section-head h2 { margin: 0; font-size: 1.3rem; }
.muted { color: var(--muted); font-size: 0.9rem; }

/* ---------- Post list ---------- */
.post-list { display: flex; flex-direction: column; gap: 16px; }
.post-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
  transition: box-shadow 0.18s ease, transform 0.18s ease;
}
.post-card:hover {
  box-shadow: 0 8px 24px rgba(31, 35, 40, 0.08);
  transform: translateY(-2px);
}
.post-card__title {
  display: block;
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}
.post-card__title:hover { color: var(--accent); text-decoration: none; }
.post-card__meta {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 8px;
}
.post-card__excerpt { margin: 0; color: #3b4149; }

/* ---------- Tags ---------- */
.tags { display: inline-flex; gap: 6px; flex-wrap: wrap; }
.tag {
  display: inline-block;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.78rem;
  padding: 2px 10px;
  border-radius: 999px;
  font-weight: 500;
}
.tag:hover { text-decoration: none; background: #e4dffe; }
.tag.active { background: var(--accent); color: #fff; }
.tag .count { opacity: 0.7; }

.tag-cloud { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 24px; }
.tag-cloud .tag { font-size: 0.9rem; padding: 6px 14px; }

/* ---------- Post detail ---------- */
.post { padding-top: 28px; }
.post-header { border-bottom: 1px solid var(--border); padding-bottom: 18px; margin-bottom: 24px; }
.post-header h1 { margin: 0 0 12px; font-size: 2rem; line-height: 1.3; }
.post-meta { display: flex; align-items: center; gap: 14px; color: var(--muted); font-size: 0.9rem; flex-wrap: wrap; }
.back-link { margin-top: 36px; }
.back-link a { font-weight: 500; }
.loading, .error { color: var(--muted); text-align: center; padding: 40px 0; }

/* ---------- Markdown body ---------- */
.markdown-body { font-size: 1.02rem; }
.markdown-body h1, .markdown-body h2, .markdown-body h3 {
  line-height: 1.35; margin: 1.6em 0 0.7em; font-weight: 700;
}
.markdown-body h1 { font-size: 1.7rem; }
.markdown-body h2 {
  font-size: 1.35rem;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
}
.markdown-body h3 { font-size: 1.12rem; }
.markdown-body p { margin: 0.9em 0; }
.markdown-body ul, .markdown-body ol { padding-left: 1.4em; margin: 0.9em 0; }
.markdown-body li { margin: 0.35em 0; }
.markdown-body blockquote {
  margin: 1.2em 0;
  padding: 8px 18px;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 8px 8px 0;
  color: #3b4149;
}
.markdown-body code {
  font-family: var(--mono);
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.9em;
}
.markdown-body pre {
  background: #1f2328;
  color: #f6f8fa;
  padding: 16px 18px;
  border-radius: 10px;
  overflow-x: auto;
  margin: 1.2em 0;
}
.markdown-body pre code { background: none; padding: 0; color: inherit; font-size: 0.9rem; }
.markdown-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.2em 0;
  font-size: 0.95rem;
}
.markdown-body th, .markdown-body td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: left;
}
.markdown-body th { background: var(--bg-soft); font-weight: 600; }
.markdown-body img { max-width: 100%; border-radius: 10px; }
.markdown-body hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg);
  padding: 24px 0;
  margin-top: 40px;
}
.site-footer p { margin: 0; text-align: center; color: var(--muted); font-size: 0.88rem; }

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
  .hero { padding: 28px 18px; }
  .hero__title { font-size: 1.5rem; }
  .post-header h1 { font-size: 1.5rem; }
  .nav { gap: 16px; }
}