:root {
  --ink: #14233a;
  --muted: #4a5b73;
  --line: #d7e0ee;
  --paper: #ffffff;
  --band: #f3f6fc;
  --brand: #1e4bd2;
  --brand-dark: #15389e;
  --accent: #0b8f6a;
  --warn: #b45309;
  --footer: #0e1a2e;
  --radius: 6px;
  --max: 1080px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font: 16px/1.75 "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: #fff;
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 700;
  font-size: 18px;
}
.brand:hover { text-decoration: none; }
.brand svg { flex-shrink: 0; }

.nav { display: flex; gap: 6px; }
.nav a {
  padding: 8px 14px;
  color: var(--ink);
  border-radius: var(--radius);
}
.nav a:hover { background: var(--band); text-decoration: none; }
.nav a.current {
  background: var(--brand);
  color: #fff;
}

.hero {
  padding: 48px 0 40px;
  background: linear-gradient(180deg, #eaf0fb 0%, #fff 88%);
  border-bottom: 1px solid var(--line);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.9fr;
  gap: 36px;
  align-items: start;
}
.hero h1 {
  margin: 0 0 14px;
  font-size: 32px;
  line-height: 1.3;
}
.lead { margin: 0 0 18px; color: var(--muted); font-size: 17px; }
.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: var(--radius);
  font-weight: 600;
  border: 1px solid transparent;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { background: #fff; color: var(--brand); border-color: var(--brand); }
.btn-macos { background: #111; color: #fff; }
.btn-ios { background: #374151; color: #fff; }
.btn-android { background: var(--accent); color: #fff; }

.dl-panel {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
  box-shadow: 0 10px 28px rgba(20, 35, 58, 0.06);
}
.dl-panel h2 { margin: 0 0 10px; font-size: 20px; }
.dl-panel p { margin: 0 0 14px; color: var(--muted); }
.dl-panel .stack { display: grid; gap: 10px; }

.band { padding: 48px 0; }
.band-alt { background: var(--band); }
.band h2 { margin: 0 0 14px; font-size: 24px; }
.band p { margin: 0 0 14px; }
.band ul, .band ol { margin: 0 0 14px; padding-left: 20px; }
.band li { margin-bottom: 8px; }

.feature-row {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 16px;
  margin-bottom: 22px;
}
.icon-box {
  width: 56px;
  height: 56px;
  border-radius: 8px;
  background: #e4ecfb;
  display: grid;
  place-items: center;
}
.data-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
}
.data-table th, .data-table td {
  border: 1px solid var(--line);
  padding: 10px 12px;
  text-align: left;
}
.data-table th { background: #e8eef9; }

.faq-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 12px;
}
.faq-item h3 { margin: 0 0 8px; font-size: 17px; }
.faq-item p { margin: 0; color: var(--muted); }

.cta-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 22px;
  background: #15389e;
  color: #fff;
  border-radius: 8px;
}
.cta-bar p { margin: 0; color: #dbe6ff; }
.cta-bar strong { color: #fff; }

.site-footer {
  background: var(--footer);
  color: #c5d0df;
  padding: 36px 0 28px;
  margin-top: 20px;
  font-size: 14px;
}
.site-footer a { color: #9ec0ff; }
.foot-nav { display: flex; gap: 16px; margin-bottom: 14px; }
.safe { color: #86efac; margin-bottom: 10px; }
.legal { color: #8fa0b5; }

@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .site-header .wrap { flex-direction: column; padding: 12px 0; gap: 8px; }
  .hero h1 { font-size: 26px; }
  .cta-bar { display: block; }
  .cta-bar .btn { margin-top: 12px; }
}