:root {
  --bg: #faf9f7;
  --panel: #ffffff;
  --text: #2b2724;
  --muted: #8a8278;
  --line: #e8e4dd;
  --accent: #a05a2c;
  --accent-soft: #f3e6db;
  --code-bg: #f3f1ec;
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1a18;
    --panel: #242220;
    --text: #e8e3dc;
    --muted: #9a9288;
    --line: #36322e;
    --accent: #d99a6c;
    --accent-soft: #3a2c21;
    --code-bg: #2b2825;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

.layout {
  display: flex;
  min-height: 100vh;
}

/* ---------- 侧栏 ---------- */
.sidebar {
  width: 280px;
  flex-shrink: 0;
  padding: 2.5rem 2rem;
  border-right: 1px solid var(--line);
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.sidebar .brand {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--text);
}
.sidebar .brand:hover { text-decoration: none; }

.sidebar .tagline {
  margin: 0;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.6;
}

.sidebar nav { flex: 1; overflow-y: auto; }

.sidebar .nav-group {
  margin: 1.1rem 0 0.35rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-transform: uppercase;
}
.sidebar .nav-group:first-child { margin-top: 0; }

.sidebar nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar nav li {
  padding: 0.35rem 0;
  border-bottom: 1px dotted var(--line);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
}

.sidebar nav a { color: var(--text); font-size: 0.95rem; }
.sidebar nav a.active { color: var(--accent); font-weight: 600; }

.sidebar .date { font-size: 0.75rem; color: var(--muted); white-space: nowrap; }

.sidebar footer {
  font-size: 0.75rem;
  color: var(--muted);
}

/* ---------- 主内容 ---------- */
.content {
  flex: 1;
  max-width: 46rem;
  padding: 3.5rem 3rem 5rem;
  margin: 0 auto;
}

.hero { margin-bottom: 2.5rem; }
.hero h1 {
  font-size: 2.1rem;
  margin: 0 0 0.5rem;
  letter-spacing: 0.02em;
}
.hero p { margin: 0; color: var(--muted); }

.section { margin-bottom: 2.5rem; }
.section-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  border-bottom: 2px solid var(--accent);
  display: inline-block;
  padding-bottom: 0.25rem;
  margin: 0 0 1.1rem;
}

.cards { display: flex; flex-direction: column; gap: 1.25rem; }

.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  transition: border-color 0.2s;
}
.card:hover { border-color: var(--accent); }

.card h2 { margin: 0 0 0.4rem; font-size: 1.25rem; }
.card h2 a { color: var(--text); }
.card h2 a:hover { color: var(--accent); text-decoration: none; }

.meta { font-size: 0.8rem; color: var(--muted); margin: 0 0 0.6rem; }

.excerpt { margin: 0 0 0.8rem; color: var(--muted); font-size: 0.92rem; }

.read-more { font-size: 0.88rem; font-weight: 600; }

.tag {
  display: inline-block;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 999px;
  padding: 0.05rem 0.6rem;
  font-size: 0.75rem;
  margin-left: 0.15rem;
}

.empty {
  background: var(--panel);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  padding: 2rem;
  color: var(--muted);
}
.empty code { background: var(--code-bg); padding: 0.1rem 0.35rem; border-radius: 4px; }

/* ---------- 笔记正文 ---------- */
.note header {
  border-bottom: 1px solid var(--line);
  padding-bottom: 1.25rem;
  margin-bottom: 2rem;
}
.note header h1 { margin: 0 0 0.4rem; font-size: 1.9rem; line-height: 1.4; }

.prose { font-size: 1.02rem; }

.prose h1, .prose h2, .prose h3, .prose h4 {
  line-height: 1.45;
  margin: 2.2em 0 0.8em;
  letter-spacing: 0.01em;
}
.prose h1 { font-size: 1.6rem; padding-bottom: 0.4em; border-bottom: 1px solid var(--line); }
.prose h2 { font-size: 1.35rem; }
.prose h3 { font-size: 1.15rem; }
.prose h4 { font-size: 1.02rem; }

.prose p { margin: 0 0 1.2em; }
.prose strong { font-weight: 650; }

.prose a { text-decoration: underline; text-underline-offset: 3px; }
.prose a:hover { text-decoration: none; }

.prose ul, .prose ol { margin: 0 0 1.2em; padding-left: 1.6em; }
.prose li { margin: 0.3em 0; }

.prose blockquote {
  margin: 1.5em 0;
  padding: 0.2em 0 0.2em 1.1em;
  border-left: 3px solid var(--accent);
  color: var(--muted);
  background: var(--accent-soft);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.prose blockquote p { margin: 0.5em 0; }

.prose code {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

.prose pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  overflow-x: auto;
  margin: 1.4em 0;
}
.prose pre code { background: none; padding: 0; font-size: 0.86em; line-height: 1.6; }

.prose table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.4em 0;
  font-size: 0.95em;
}
.prose th, .prose td {
  border: 1px solid var(--line);
  padding: 0.5em 0.9em;
  text-align: left;
}
.prose th { background: var(--accent-soft); font-weight: 600; }

.prose img { max-width: 100%; border-radius: var(--radius); }

.prose hr { border: none; border-top: 1px solid var(--line); margin: 2em 0; }

.note-nav { margin-top: 3rem; padding-top: 1.25rem; border-top: 1px solid var(--line); font-size: 0.9rem; }

/* ---------- 移动端 ---------- */
@media (max-width: 800px) {
  .layout { flex-direction: column; }
  .sidebar {
    position: static;
    width: 100%;
    height: auto;
    padding: 1.5rem 1.25rem 1rem;
    border-right: none;
    border-bottom: 1px solid var(--line);
    gap: 0.6rem;
  }
  .sidebar nav { max-height: 32vh; }
  .content { padding: 2rem 1.25rem 4rem; }
  .hero h1 { font-size: 1.7rem; }
  .note header h1 { font-size: 1.5rem; }
}