:root {
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --bg: #ffffff;
  --bg-soft: #f7f7f5;
  --accent: #0b6e4f;
  --accent-soft: #d9eee5;
  --border: #e6e6e6;
  --code-bg: #f4f4f2;
  --sidebar-w: 280px;
  --content-max: 820px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
body {
  margin: 0; padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--fg);
  background: var(--bg);
}

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

/* ---------- layout ---------- */
.layout {
  display: flex;
  align-items: flex-start;
  min-height: 100vh;
}

aside.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--bg-soft);
  border-right: 1px solid var(--border);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 28px 22px 24px;
}
aside.sidebar h1 {
  font-size: 18px;
  margin: 0 0 4px;
  letter-spacing: -0.01em;
  line-height: 1.3;
}
aside.sidebar .subtitle {
  color: var(--muted);
  font-size: 12.5px;
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
aside.sidebar .authors {
  font-size: 13px;
  color: var(--fg);
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 18px;
  line-height: 1.55;
}
aside.sidebar .authors strong {
  display: block;
  color: var(--muted);
  font-weight: 500;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}

aside.sidebar nav ol {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: tocnum;
}
aside.sidebar nav li { margin: 0; }
aside.sidebar nav a {
  display: block;
  padding: 6px 10px 6px 12px;
  border-left: 2px solid transparent;
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.4;
  transition: color 0.12s ease, border-color 0.12s ease, background 0.12s ease;
}
aside.sidebar nav a:hover {
  color: var(--accent);
  text-decoration: none;
  background: rgba(11, 110, 79, 0.05);
}
aside.sidebar nav a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  font-weight: 600;
  background: rgba(11, 110, 79, 0.07);
}
aside.sidebar nav .num {
  display: inline-block;
  width: 22px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
}
aside.sidebar nav a.active .num { color: var(--accent); }

aside.sidebar .top-link {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
  font-size: 12.5px;
}

/* ---------- main column ---------- */
main {
  flex: 1;
  min-width: 0;
  padding: 36px 40px 80px;
}
main .content {
  max-width: var(--content-max);
  margin: 0 auto;
}

main h1.section-title {
  font-size: 26px;
  margin-top: 0;
  border-bottom: 2px solid var(--accent-soft);
  padding-bottom: 8px;
}
main h2 { font-size: 19px; margin-top: 26px; }
main h3 {
  font-size: 14.5px;
  margin-top: 22px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
section.doc-section {
  padding-top: 28px;
  margin-top: 28px;
  border-top: 1px solid var(--border);
  scroll-margin-top: 16px;
}
section.doc-section:first-of-type {
  border-top: none;
  margin-top: 0;
  padding-top: 0;
}

p, li { font-size: 15.5px; }
code {
  background: var(--code-bg);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 13.5px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
}
pre {
  background: var(--code-bg);
  padding: 14px 16px;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.55;
  border: 1px solid var(--border);
}
pre code { background: transparent; padding: 0; }

table {
  border-collapse: collapse;
  margin: 16px 0;
  width: 100%;
  font-size: 14.5px;
}
table th, table td {
  border-bottom: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}
table th { background: var(--bg-soft); font-weight: 600; }
table tr:hover td { background: #fafafa; }

blockquote {
  border-left: 3px solid var(--accent-soft);
  padding: 4px 14px;
  margin: 16px 0;
  color: var(--muted);
}

/* ---------- figures ---------- */
main img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 22px auto 6px;
}
main p:has(> img) {
  text-align: center;
  margin: 0;
}


/* ---------- hero / KPIs on first section ---------- */
.hero {
  padding: 28px 0 8px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
}
.hero h1 {
  font-size: 30px;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
  border: none;
  padding: 0;
}
.hero .lede {
  color: var(--muted);
  font-size: 15.5px;
  max-width: 680px;
  margin: 0 0 20px;
}
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 10px;
  margin: 18px 0 18px;
}
.kpi {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
}
.kpi .label {
  font-size: 11.5px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}
.kpi .value {
  font-size: 20px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: -0.01em;
}

footer.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  padding: 18px 24px;
  margin-top: 60px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

/* ---------- mobile ---------- */
.menu-toggle {
  display: none;
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 50;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0,0,0,0.12);
}

@media (max-width: 900px) {
  .menu-toggle { display: block; }
  aside.sidebar {
    position: fixed;
    left: -300px;
    top: 0;
    height: 100vh;
    width: 280px;
    z-index: 40;
    transition: left 0.22s ease;
    box-shadow: 4px 0 14px rgba(0,0,0,0.06);
  }
  aside.sidebar.open { left: 0; }
  main { padding: 60px 22px 60px; }
  .hero h1 { font-size: 24px; }
}