:root {
  --fg: #1b1f24;
  --muted: #57606a;
  --bg: #ffffff;
  --accent: #0b5cad;
  --border: #d0d7de;
  --card-bg: #f6f8fa;
  --max: 860px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
}

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

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: var(--card-bg);
  padding: 0.1em 0.35em;
  border-radius: 4px;
  font-size: 0.9em;
}

pre {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  overflow-x: auto;
}
pre code { background: none; padding: 0; }

.muted { color: var(--muted); }

/* Header / footer */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  max-width: var(--max);
  margin: 0 auto;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
}
.site-title { font-weight: 700; font-size: 1.1rem; color: var(--fg); }
.site-nav a { margin-left: 1rem; }

.site-main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

.site-footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.5rem 1.25rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}

/* Home */
.intro h1 { margin-bottom: 0.25rem; }

.card-grid {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}
.card {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card-bg);
  transition: border-color 0.15s ease;
}
.card:hover { border-color: var(--accent); }
.card-link { display: block; padding: 1rem 1.1rem; color: var(--fg); }
.card-link:hover { text-decoration: none; }
.card h2 { margin: 0 0 0.4rem; font-size: 1.05rem; color: var(--accent); }
.card p { margin: 0; color: var(--muted); font-size: 0.92rem; }
.card-repo {
  display: inline-block;
  margin: 0 1.1rem 1rem;
  font-size: 0.85rem;
  color: var(--muted);
}
.card-repo:hover { color: var(--accent); }

/* Subsystem + doc lists */
.breadcrumb { color: var(--muted); font-size: 0.9rem; margin-bottom: 1rem; }

.doc-list { list-style: none; padding: 0; margin: 1.5rem 0 0; }
.doc-item {
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--border);
}
.doc-item p { margin: 0.3rem 0 0; color: var(--muted); font-size: 0.92rem; }

.source-link { font-size: 0.9rem; }

.doc-body { margin-top: 1.5rem; }
.doc-header { border-bottom: 1px solid var(--border); padding-bottom: 0.75rem; }

.empty, .muted.empty { color: var(--muted); font-style: italic; }