:root {
  --bg: #f6f3ef;
  --surface: #ffffff;
  --ink: #171717;
  --ink-soft: #5b5b5b;
  --accent: #d45113;
  --accent-soft: rgba(212, 81, 19, 0.1);
  --border: rgba(0, 0, 0, 0.12);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  color: var(--ink);
  background: radial-gradient(1000px 700px at 20% 0%, #fff, transparent 60%), var(--bg);
}
main { max-width: 980px; margin: 0 auto; padding: 28px 16px 56px; }
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.9);
  position: sticky;
  top: 10px;
  backdrop-filter: blur(4px);
  z-index: 10;
}
.nav a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
}
.hero { margin: 20px 0 14px; }
h1 {
  margin: 0 0 8px;
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  line-height: 1.15;
}
p.lead {
  margin: 0;
  color: var(--ink-soft);
  max-width: 780px;
}
.card {
  margin-top: 16px;
  padding: 18px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
}
.callout {
  background: var(--accent-soft);
  border: 1px solid rgba(212, 81, 19, 0.25);
}
h2 {
  font-size: 1.2rem;
  margin: 0 0 10px;
}
h3 {
  font-size: 1rem;
  margin: 14px 0 8px;
}
p { line-height: 1.65; color: var(--ink-soft); margin: 0 0 10px; }
ul, ol {
  margin: 8px 0 0;
  padding-left: 18px;
  line-height: 1.65;
  color: var(--ink-soft);
}
.table-wrap { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}
th, td {
  border: 1px solid var(--border);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}
th {
  background: #faf7f3;
  color: #6b2d0f;
}
.diagram {
  border: 1px dashed rgba(212, 81, 19, 0.45);
  border-radius: 12px;
  padding: 10px;
  background: #fffaf6;
  overflow-x: auto;
}
.diagram pre {
  margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.82rem;
  line-height: 1.4;
  color: #7b3513;
}
.footer {
  margin-top: 24px;
  font-size: 0.88rem;
  color: var(--ink-soft);
}
@media (max-width: 700px) {
  main { padding: 20px 12px 40px; }
  .card { padding: 14px; }
}