:root {
  color-scheme: light;
  --ink: #131b2e;
  --muted: #596176;
  --line: #dbe0ef;
  --paper: #ffffff;
  --surface: #f5f7ff;
  --blue: #1d4ed8;
  --navy: #131a33;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 15px;
  line-height: 1.7;
}
a { color: var(--blue); }
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, .94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}
.nav {
  width: min(1180px, calc(100% - 40px));
  height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.logo { display: block; width: 190px; height: auto; }
.back {
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}
.back:hover { color: var(--blue); }
.layout {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: 56px 0 80px;
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}
.toc {
  position: sticky;
  top: 104px;
  padding-right: 24px;
  border-right: 1px solid var(--line);
}
.toc strong {
  display: block;
  margin-bottom: 14px;
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  text-transform: uppercase;
}
.toc a {
  display: block;
  padding: 7px 0;
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
}
.toc a:hover { color: var(--blue); }
.document {
  min-width: 0;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: clamp(28px, 5vw, 64px);
}
.eyebrow {
  margin: 0 0 12px;
  color: var(--blue);
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}
h1, h2, h3 { font-family: "Plus Jakarta Sans", sans-serif; line-height: 1.25; }
h1 { margin: 0; font-size: clamp(32px, 5vw, 48px); }
h2 { margin: 48px 0 14px; padding-top: 8px; font-size: 24px; }
h3 { margin: 26px 0 8px; font-size: 17px; }
.lead { max-width: 760px; margin: 20px 0 0; color: var(--muted); font-size: 17px; }
.updated {
  display: inline-block;
  margin-top: 24px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--muted);
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
}
p, li { color: #343b4e; }
ul { padding-left: 22px; }
.notice {
  margin: 28px 0;
  padding: 18px 20px;
  border-left: 4px solid var(--blue);
  background: #eef3ff;
}
.contact {
  margin-top: 44px;
  padding: 22px;
  background: var(--navy);
  color: white;
  border-radius: 6px;
}
.contact h2 { margin: 0 0 8px; padding: 0; color: white; }
.contact p { margin: 0; color: #dbe1ff; }
.contact a { color: white; font-weight: 700; }
.footer { padding: 28px 20px; background: var(--navy); color: #bfc7dd; text-align: center; font-size: 13px; }
.footer a { color: white; }
@media (max-width: 840px) {
  .layout { grid-template-columns: 1fr; padding-top: 32px; }
  .toc { position: static; display: none; }
  .document { padding: 28px 22px; }
  .logo { width: 160px; }
}