:root {
  --ink: #12141a;
  --muted: #5a6170;
  --line: #e4e6eb;
  --bg: #fafafa;
  --card: #ffffff;
  --accent: #1a4d8c;
  --accent-hover: #143a6b;
  --max: 42rem;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "IBM Plex Sans", system-ui, -apple-system, Segoe UI, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  font-size: 1.05rem;
}
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-hover); }
.wrap { max-width: var(--max); margin: 0 auto; padding: 1.5rem 1.25rem 4rem; }
header.site {
  border-bottom: 1px solid var(--line);
  background: var(--card);
}
header.site .inner {
  max-width: 56rem;
  margin: 0 auto;
  padding: 0.9rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
}
.logo {
  font-weight: 650;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
}
.logo:hover { color: var(--accent); }
.nav a { margin-left: 1rem; font-size: 0.95rem; color: var(--muted); text-decoration: none; }
.nav a:hover { color: var(--accent); }
h1 {
  font-size: clamp(1.75rem, 4vw, 2.35rem);
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin: 1.75rem 0 0.75rem;
}
h2 {
  font-size: 1.25rem;
  margin: 2rem 0 0.6rem;
  letter-spacing: -0.02em;
}
p { margin: 0.65rem 0; }
.lede { font-size: 1.15rem; color: var(--muted); margin-bottom: 1.5rem; }
.spine {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.1rem 1.25rem;
  margin: 1.5rem 0;
}
.spine ol { margin: 0.4rem 0 0; padding-left: 1.2rem; }
.spine li { margin: 0.45rem 0; }
.guide-list { list-style: none; padding: 0; margin: 1rem 0 2rem; }
.guide-list li {
  border-bottom: 1px solid var(--line);
  padding: 0.85rem 0;
}
.guide-list a {
  color: var(--ink);
  text-decoration: none;
  font-weight: 550;
}
.guide-list a:hover { color: var(--accent); }
.guide-list .meta { display: block; color: var(--muted); font-size: 0.92rem; font-weight: 400; margin-top: 0.2rem; }
.cta {
  background: var(--ink);
  color: #fff;
  border-radius: 10px;
  padding: 1.25rem 1.35rem;
  margin: 2.25rem 0 1rem;
}
.cta h2 { color: #fff; margin-top: 0; }
.cta p { color: #d7dbe3; }
.cta a.btn {
  display: inline-block;
  margin-top: 0.75rem;
  background: #fff;
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
  padding: 0.65rem 1rem;
  border-radius: 7px;
}
.cta a.btn:hover { background: #eef1f6; }
.check { list-style: none; padding: 0; }
.check li {
  position: relative;
  padding: 0.7rem 0 0.7rem 1.7rem;
  border-bottom: 1px solid var(--line);
}
.check li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1rem;
  width: 0.85rem;
  height: 0.85rem;
  border: 2px solid var(--accent);
  border-radius: 3px;
}
.note {
  color: var(--muted);
  font-size: 0.95rem;
  border-left: 3px solid var(--line);
  padding-left: 0.9rem;
  margin: 1.25rem 0;
}
footer.site {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
  padding: 1.5rem 1.25rem 2.5rem;
  text-align: center;
}
footer.site a { color: var(--muted); }
@media (max-width: 560px) {
  .nav a { margin-left: 0.65rem; }
}