:root {
  --bg: #f6f4ef;
  --surface: #ffffff;
  --ink: #1a1f1c;
  --muted: #5c675f;
  --line: #d9ddd6;
  --accent: #0f6b4c;
  --accent-ink: #ffffff;
  --max: 1100px;
  --font: "IBM Plex Sans", "Segoe UI", "Helvetica Neue", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #dceee4 0%, transparent 55%),
    radial-gradient(900px 400px at 100% 0%, #e8e2d4 0%, transparent 50%),
    var(--bg);
  line-height: 1.55;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: #0a4d37; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(8px);
  background: rgba(246, 244, 239, 0.92);
  border-bottom: 1px solid var(--line);
}

.topbar-inner,
.footer-inner,
.hero,
.section,
.guide-layout {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
}

.brand {
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
}

.topbar-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1rem;
  font-size: 0.92rem;
}

.topbar-nav a {
  color: var(--muted);
  text-decoration: none;
}

.topbar-nav a:hover { color: var(--ink); }

.main { flex: 1; padding: 2rem 0 3rem; }

.hero {
  padding: 1.5rem 0 2rem;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.75rem;
  color: var(--muted);
  margin: 0 0 0.75rem;
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.lede {
  max-width: 42rem;
  color: var(--muted);
  margin: 0 0 1.25rem;
  font-size: 1.05rem;
}

.cta-row,
.ref-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 0.95rem;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
}

.btn:hover { border-color: var(--accent); color: var(--accent); }

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}

.btn.primary:hover {
  background: #0a4d37;
  border-color: #0a4d37;
  color: var(--accent-ink);
}

.btn.small { padding: 0.35rem 0.7rem; font-size: 0.85rem; }

.section { margin-top: 2.25rem; }

.section h2 {
  margin: 0 0 1rem;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.steps {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
}

.steps li { margin-bottom: 0.4rem; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.85rem;
}

.card {
  display: block;
  padding: 1rem 1.05rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  text-decoration: none;
  color: inherit;
  transition: border-color 120ms ease, transform 120ms ease;
}

.card:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

.card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
}

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

.ref-row a {
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  text-decoration: none;
  color: var(--ink);
  font-size: 0.9rem;
}

.ref-row a:hover { border-color: var(--accent); color: var(--accent); }

.guide-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 1.5rem;
  align-items: start;
}

.toc {
  position: sticky;
  top: 4.5rem;
  max-height: calc(100vh - 5.5rem);
  overflow: auto;
  padding: 0.75rem 0.85rem;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 0.85rem;
}

.toc-title {
  margin: 0 0 0.5rem;
  font-weight: 600;
  color: var(--ink);
}

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

.toc li { margin: 0.35rem 0; }

.toc a {
  color: var(--muted);
  text-decoration: none;
}

.toc a:hover { color: var(--accent); }

.guide-body {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.25rem 1.4rem 2rem;
}

.guide-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}

.prose h1 {
  margin-top: 0;
  font-size: 1.85rem;
  letter-spacing: -0.02em;
}

.prose h2 {
  margin-top: 2rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--line);
  font-size: 1.3rem;
}

.prose h3 { margin-top: 1.4rem; font-size: 1.08rem; }

.prose p, .prose li { color: #2a322e; }

.prose code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: #eef2ee;
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.prose pre {
  overflow: auto;
  background: #16201b;
  color: #e8f0ea;
  padding: 0.9rem 1rem;
  border-radius: 8px;
  font-size: 0.85rem;
}

.prose pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin: 1rem 0;
}

.prose th,
.prose td {
  border: 1px solid var(--line);
  padding: 0.45rem 0.6rem;
  text-align: left;
  vertical-align: top;
}

.prose th { background: #eef2ee; }

.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 1.5rem 0;
}

.footer {
  border-top: 1px solid var(--line);
  padding: 1rem 0 1.4rem;
  color: var(--muted);
  font-size: 0.85rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
}

.footer a { color: var(--muted); text-decoration: none; }
.footer a:hover { color: var(--accent); }

@media (max-width: 860px) {
  .guide-layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
    max-height: none;
  }
}