:root {
  --ink: #1c2333;
  --ink-soft: #4a5268;
  --bg: #fdfcfb;
  --sky: #0ea5e9;
  --indigo: #6366f1;
  --border: #e5e2dc;
  --code-bg: #f4f2ee;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}

.site-header {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(135deg, var(--sky), var(--indigo));
}

.site-title {
  color: white;
  font-weight: 700;
  text-decoration: none;
  font-size: 1.1rem;
}

.layout {
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
}

.sidebar {
  width: 260px;
  flex-shrink: 0;
  padding: 1.5rem 1rem;
  border-right: 1px solid var(--border);
}

.sidebar h3 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  margin: 1.25rem 0 0.4rem;
}

.sidebar ul { list-style: none; padding: 0; margin: 0; }
.sidebar li { margin: 0.15rem 0; }
.sidebar a { color: var(--ink); text-decoration: none; font-size: 0.9rem; }
.sidebar a:hover { color: var(--sky); }

.content {
  flex: 1;
  padding: 2rem 2.5rem;
  min-width: 0;
  max-width: 800px;
}

.content h1 { font-size: 1.8rem; }
.content h2 { font-size: 1.3rem; margin-top: 2rem; border-bottom: 1px solid var(--border); padding-bottom: 0.3rem; }
.content h3 { font-size: 1.05rem; margin-top: 1.5rem; }

.content table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
  font-size: 0.9rem;
  overflow-x: auto;
  display: block;
}
.content th, .content td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.7rem;
  text-align: left;
}
.content th { background: var(--code-bg); }

.content code {
  background: var(--code-bg);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-size: 0.88em;
}
.content pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
}
.content pre code { background: none; padding: 0; }

.content .markdown-alert {
  border-left: 4px solid var(--sky);
  background: var(--code-bg);
  padding: 0.75rem 1rem;
  border-radius: 0 8px 8px 0;
  margin: 1rem 0;
}
.content .markdown-alert-title {
  font-weight: 700;
  display: block;
  margin-bottom: 0.25rem;
}
.content .markdown-alert.markdown-alert-warning,
.content .markdown-alert.markdown-alert-caution {
  border-left-color: #dc6803;
}
.content .markdown-alert.markdown-alert-important {
  border-left-color: var(--indigo);
}

.content pre.mermaid {
  background: white;
  border: 1px solid var(--border);
  text-align: center;
}

@media (max-width: 800px) {
  .layout { flex-direction: column; }
  .sidebar { width: 100%; border-right: none; border-bottom: 1px solid var(--border); }
}