:root {
  --bg: #fafafa;
  --fg: #1a1a1a;
  --accent: #2563eb;
  --accent-light: #dbeafe;
  --border: #e5e7eb;
  --code-bg: #f3f4f6;
  --code-fg: #111827;
  --nav-bg: #111827;
  --nav-fg: #e5e7eb;
  --layer-bg: #f9fafb;
  --tip-bg: #ecfdf5;
  --tip-border: #10b981;
  --warn-bg: #fffbeb;
  --warn-border: #f59e0b;
  --info-bg: #eff6ff;
  --info-border: #3b82f6;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
nav {
  background: var(--nav-bg);
  color: var(--nav-fg);
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}
nav .logo { font-weight: 700; font-size: 1.25rem; color: #fff; }
nav a { color: var(--nav-fg); font-size: 0.875rem; }
nav a:hover { color: #fff; text-decoration: none; }
nav a.github-link { margin-left: auto; }
.container { max-width: 960px; margin: 0 auto; padding: 2rem; }
h1 { font-size: 2.5rem; margin-bottom: 0.5rem; }
h2 { font-size: 1.75rem; margin-top: 3rem; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--border); }
h3 { font-size: 1.25rem; margin-top: 2rem; margin-bottom: 0.75rem; }
h4 { font-size: 1.1rem; margin-top: 1.5rem; margin-bottom: 0.5rem; }
p { margin-bottom: 1rem; }
ul, ol { margin-bottom: 1rem; padding-left: 1.5rem; }
li { margin-bottom: 0.25rem; }
pre {
  background: var(--code-bg);
  color: var(--code-fg);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  line-height: 1.5;
  border: 1px solid var(--border);
}
code {
  background: var(--code-bg);
  padding: 0.15em 0.35em;
  border-radius: 3px;
  font-size: 0.9em;
}
pre code { background: none; padding: 0; }
table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
}
th, td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
}
th { background: var(--code-bg); font-weight: 600; }
.hero {
  text-align: center;
  padding: 3rem 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
}
.hero p { font-size: 1.2rem; color: #6b7280; }
.arch-diagram {
  background: var(--code-bg);
  padding: 1.5rem;
  border-radius: 8px;
  font-family: monospace;
  white-space: pre;
  overflow-x: auto;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
  font-size: 0.85rem;
  line-height: 1.4;
}
.layer-card {
  background: var(--layer-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}
.layer-card h4 { margin-top: 0; color: var(--accent); }
.badge {
  display: inline-block;
  background: var(--accent-light);
  color: var(--accent);
  padding: 0.15em 0.5em;
  border-radius: 4px;
  font-size: 0.8em;
  font-weight: 600;
}
.note {
  background: var(--warn-bg);
  border-left: 4px solid var(--warn-border);
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  border-radius: 0 6px 6px 0;
}
.tip {
  background: var(--tip-bg);
  border-left: 4px solid var(--tip-border);
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  border-radius: 0 6px 6px 0;
}
.info {
  background: var(--info-bg);
  border-left: 4px solid var(--info-border);
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  border-radius: 0 6px 6px 0;
}
footer {
  text-align: center;
  padding: 2rem;
  color: #9ca3af;
  border-top: 1px solid var(--border);
  margin-top: 3rem;
}
.page-header {
  padding: 2rem 0 1rem;
  margin-bottom: 1rem;
}
.page-header h1 { margin-bottom: 0.25rem; }
.page-header p { color: #6b7280; font-size: 1.1rem; }
.breadcrumb {
  font-size: 0.875rem;
  color: #6b7280;
  margin-bottom: 1rem;
}
.breadcrumb a { color: var(--accent); }
.toc {
  background: var(--layer-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem 1.25rem 1.25rem 1rem;
  margin-bottom: 2rem;
}
.toc h4 { margin-top: 0; margin-bottom: 0.5rem; font-size: 0.95rem; color: #6b7280; }
.toc ul { list-style: none; padding-left: 0; margin-bottom: 0; }
.toc li { margin-bottom: 0.35rem; }
.toc a { font-size: 0.9rem; }
.comment { color: #6b7280; }
.highlight { color: var(--accent); font-weight: 600; }
dt { font-weight: 600; margin-top: 1rem; }
dd { margin-left: 1.5rem; margin-bottom: 0.5rem; }