/* 第 1 套：顶栏 + 宽屏双列 Hero + 三列功能卡，商务蓝 */
:root {
  --bg: #f4f7fb;
  --card: #ffffff;
  --ink: #1c2a3a;
  --muted: #5b6b7c;
  --line: #d7e1ec;
  --brand: #1e5aa8;
  --brand-dark: #15427c;
  --accent: #e85d04;
  --ok: #1b7f4e;
}
* { 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(--bg);
  line-height: 1.75;
  font-size: 16px;
}
img, svg { max-width: 100%; vertical-align: middle; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }

.topbar {
  background: #12325f;
  color: #d7e6f7;
  font-size: 13px;
  padding: 8px 0;
}
.topbar .wrap { display: flex; justify-content: space-between; gap: 16px; }

.site-header {
  background: #fff;
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}
.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 700;
  font-size: 20px;
  text-decoration: none;
}
.brand:hover { text-decoration: none; color: var(--brand); }
.nav {
  display: flex;
  gap: 8px;
}
.nav a {
  padding: 8px 16px;
  color: var(--ink);
  border-radius: 6px;
  font-weight: 600;
}
.nav a.is-current {
  background: var(--brand);
  color: #fff;
  text-decoration: none;
}

.hero {
  background: linear-gradient(120deg, #14396f 0%, #1e5aa8 58%, #2a7bd4 100%);
  color: #fff;
  padding: 56px 0 64px;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.85fr;
  gap: 36px;
  align-items: center;
}
.hero h1 {
  margin: 0 0 16px;
  font-size: 34px;
  line-height: 1.3;
}
.hero p { margin: 0 0 14px; color: #e8f1fb; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 22px; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 700;
  border: 0;
  cursor: pointer;
}
.btn-primary { background: #ffb703; color: #1c2a3a; }
.btn-primary:hover { background: #ffc53d; text-decoration: none; }
.btn-ghost { background: transparent; color: #fff; border: 1px solid #c9ddf5; }
.btn-ghost:hover { background: rgba(255,255,255,.08); text-decoration: none; }
.btn-win { background: var(--brand); color: #fff; }
.btn-win:hover { background: var(--brand-dark); text-decoration: none; }
.btn-mac { background: #222; color: #fff; }
.btn-mac:hover { text-decoration: none; opacity: .92; }
.btn-ios { background: #0f172a; color: #fff; }
.btn-android { background: #3d8b40; color: #fff; }
.dl-card {
  background: #fff;
  color: var(--ink);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 18px 40px rgba(8, 24, 48, .22);
}
.dl-card h2 { margin: 0 0 8px; font-size: 20px; }
.dl-card p { color: var(--muted); }
.dl-card .btn { width: 100%; justify-content: center; margin-top: 10px; }

.section { padding: 56px 0; }
.section h2 { font-size: 26px; margin: 0 0 12px; }
.lead { color: var(--muted); margin-bottom: 24px; }
.cards-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.card, .news-item, .faq-item, .step, .spec {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
}
.card h3, .news-item h3, .faq-item h3 { margin: 0 0 8px; font-size: 18px; }
.icon-row { display: flex; gap: 10px; margin-bottom: 12px; }
.muted { color: var(--muted); }
.date { font-size: 13px; color: var(--brand); font-weight: 700; }
.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.news-list { display: grid; gap: 14px; }
.faq-list { display: grid; gap: 12px; }
.faq-item h3 { font-size: 17px; }
.cta-band {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 28px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}
.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.specs { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }

.site-footer {
  background: #0f2138;
  color: #c9d7e6;
  padding: 36px 0 24px;
  margin-top: 20px;
}
.site-footer a { color: #fff; }
.foot-nav { display: flex; gap: 16px; margin-bottom: 16px; }
.fineprint { font-size: 13px; line-height: 1.8; color: #9fb0c3; }

@media (max-width: 900px) {
  .hero-grid, .cards-3, .compare, .platform-grid, .steps, .specs, .cta-band {
    grid-template-columns: 1fr;
  }
  .header-row, .cta-band { flex-direction: column; align-items: flex-start; }
  .nav { flex-wrap: wrap; }
}