:root {
  --bg: #0b0f14;
  --card: #121821;
  --line: #1e2a38;
  --text: #e8eef5;
  --muted: #94a3b8;
  --sky: #38bdf8;
  --em: #34d399;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}
a { color: var(--sky); }
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11, 15, 20, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.site-header-inner {
  max-width: 740px; margin: 0 auto; padding: 0.75rem 1.25rem;
  display: flex; justify-content: space-between; align-items: center; gap: 0.75rem; flex-wrap: wrap;
}
.site-header .brand {
  font-weight: 700; color: #fff; text-decoration: none; font-size: 1rem;
}
.site-header .brand:hover { color: #7dd3fc; }
.site-header nav { display: flex; gap: 0.75rem; flex-wrap: wrap; align-items: center; font-size: 0.875rem; }
.site-header nav a {
  color: #94a3b8; text-decoration: none;
  padding: 0.3rem 0.55rem; border-radius: 0.4rem;
}
.site-header nav a:hover { color: #e0f2fe; background: rgba(30, 41, 59, 0.6); }
.site-header nav a.cta-nav {
  background: #0284c7; color: #fff !important; font-weight: 600;
}
.site-header nav a.cta-nav:hover { background: #0ea5e9; }
main, .guide-wrap { max-width: 740px; margin: 0 auto; padding: 1.25rem; }
header.page-head { max-width: 740px; margin: 0 auto; padding: 1rem 1.25rem 0; }
h1 { font-size: clamp(1.5rem, 4vw, 1.85rem); line-height: 1.25; margin: 0.5rem 0 0.75rem; }
h2 { font-size: 1.2rem; margin-top: 2.25rem; color: #fff; }
h3 { font-size: 1.05rem; color: #e2e8f0; margin-top: 1.5rem; }
.muted { color: var(--muted); }
.mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: #7dd3fc; }
.box {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1rem 1.15rem;
  margin: 1.25rem 0;
}
.box.warn { border-color: #854d0e; background: #1a1508; }
.box.tip { border-color: #14532d; background: #0c1a12; }
.diagram {
  background: #080c10;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1rem;
  margin: 1.25rem 0;
  overflow-x: auto;
}
.diagram svg { display: block; margin: 0 auto; max-width: 100%; height: auto; }
.diagram figcaption {
  text-align: center; color: var(--muted); font-size: 0.85rem; margin-top: 0.75rem;
}
ul, ol { color: var(--muted); }
li { margin: 0.35rem 0; }
footer.site-foot {
  max-width: 740px; margin: 2.5rem auto 0; padding: 1.5rem 1.25rem 3rem;
  border-top: 1px solid var(--line); color: var(--muted); font-size: 0.85rem;
}
.crumbs { font-size: 0.9rem; color: var(--muted); }
.cta {
  display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1rem;
  background: #0284c7; color: #fff !important; text-decoration: none;
  border-radius: 0.5rem; font-weight: 600; font-size: 0.95rem;
}
.cta:hover { background: #0ea5e9; }