/* Set 1 — root: centered editorial column, navy paper */
:root {
  --ink: #12233a;
  --muted: #4d5d73;
  --paper: #f4f7fb;
  --card: #ffffff;
  --line: #d5deea;
  --navy: #0b3d91;
  --navy-deep: #08285f;
  --sky: #1e6fe3;
  --focus: #0a6b4d;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;
  font-size: 16px;
}
a { color: var(--navy); }
a:hover { color: var(--sky); }
.wrap { width: min(880px, calc(100% - 40px)); margin: 0 auto; }
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 20px;
}
.brand {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 28px;
  letter-spacing: 0.02em;
  color: var(--navy-deep);
  text-decoration: none;
  font-weight: 700;
}
.nav { display: flex; gap: 8px; flex-wrap: wrap; }
.nav a {
  text-decoration: none;
  padding: 8px 14px;
  color: var(--ink);
  border-radius: 999px;
}
.nav a.is-current {
  background: var(--navy);
  color: #fff;
}
.hero {
  text-align: center;
  padding: 64px 0 40px;
}
.hero h1 {
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.35;
  margin: 0 0 16px;
}
.hero .lead { color: var(--muted); font-size: 18px; margin: 0 0 28px; }
.cta-row { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  border-radius: 999px;
  padding: 14px 26px;
  font-weight: 600;
}
.btn-primary { background: var(--navy); color: #fff; }
.btn-primary:hover { background: var(--navy-deep); color: #fff; }
.btn-ghost { background: #fff; border: 1px solid var(--line); color: var(--navy); }
.icon { width: 18px; height: 18px; fill: currentColor; }
section { padding: 8px 0 36px; }
section h2 {
  font-size: 24px;
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--navy);
}
.prose p { margin: 0 0 14px; }
.platform-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
.platform-list article {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 16px 18px;
  border-radius: 8px;
}
.note {
  background: #eef4ff;
  border-left: 4px solid var(--navy);
  padding: 12px 16px;
  margin: 16px 0;
}
.faq-item { border-top: 1px solid var(--line); padding: 14px 0; }
.faq-item h3 { margin: 0 0 8px; font-size: 17px; }
.site-footer {
  background: var(--navy-deep);
  color: #d7e2f2;
  padding: 36px 0 44px;
  font-size: 14px;
}
.site-footer .brand { color: #fff; display: inline-block; margin-bottom: 12px; }
.site-footer nav { margin: 12px 0 18px; display: flex; gap: 16px; flex-wrap: wrap; }
.site-footer nav a { color: #bcd0f0; }
.site-footer p { margin: 8px 0; }
.req-table { width: 100%; border-collapse: collapse; background: #fff; }
.req-table th, .req-table td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; }
.req-table th { background: #e8eef8; }
.steps { counter-reset: s; padding: 0; list-style: none; }
.steps li { counter-increment: s; margin: 0 0 12px; padding-left: 42px; position: relative; }
.steps li::before {
  content: counter(s);
  position: absolute;
  left: 0; top: 2px;
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--navy);
  color: #fff;
  font-size: 14px;
  display: grid;
  place-items: center;
}
@media (max-width: 640px) {
  .site-header .wrap { flex-direction: column; padding: 12px 0; }
  .hero { padding-top: 36px; }
}