:root {
  --bg: #f3f3f3;
  --paper: #ffffff;
  --ink: #1b1b1b;
  --brand: #0078d4;
  --line: #e1e1e1;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: "Segoe UI", "Microsoft YaHei UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
}
a { color: var(--brand); }
.chrome {
  background: #f9f9f9;
  border-bottom: 1px solid var(--line);
  padding: 8px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand { display: flex; gap: 8px; align-items: center; text-decoration: none; color: var(--ink); font-weight: 600; }
.brand svg { width: 20px; height: 20px; }
.nav a {
  text-decoration: none;
  color: var(--ink);
  padding: 6px 10px;
  border-radius: 4px;
  margin-left: 4px;
}
.nav a.is-current { background: #e6f2fb; color: var(--brand); }
.shell {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - 48px);
}
.rail {
  background: #f9f9f9;
  border-right: 1px solid var(--line);
  padding: 16px 12px;
}
.rail p { margin: 0 0 8px; color: #616161; font-size: 12px; }
.wrap { padding: 20px 28px 48px; }
.hero {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 16px;
}
.hero h1 { margin-top: 0; font-size: 28px; font-weight: 600; }
.cta-row { display: flex; flex-wrap: wrap; gap: 8px; }
.btn {
  background: var(--brand);
  color: #fff;
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 4px;
  display: inline-flex;
  gap: 6px;
  align-items: center;
  font-weight: 600;
}
.btn-mac, .btn-ios, .btn-and { background: #323130; }
section { background: var(--paper); border: 1px solid var(--line); border-radius: 8px; padding: 18px 18px 8px; margin: 0 0 14px; }
section h2 { margin-top: 0; font-size: 20px; }
.cards-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.card, .review, .news-item, .faq-item { background: #f9f9f9; border-radius: 6px; padding: 12px; }
table { width: 100%; border-collapse: collapse; }
th { background: #e6f2fb; }
th, td { border: 1px solid var(--line); padding: 8px; text-align: left; }
.steps { display: grid; gap: 8px; }
.step { display: flex; gap: 10px; align-items: flex-start; }
.step b { background: var(--brand); color: #fff; border-radius: 4px; min-width: 28px; height: 28px; display: grid; place-items: center; }
.site-footer { background: #323130; color: #e1e1e1; padding: 20px 28px; }
.foot-nav a { color: #9dc3e6; margin-right: 12px; }
@media (max-width: 900px) {
  .shell { grid-template-columns: 1fr; }
  .cards-2 { grid-template-columns: 1fr; }
}