/* Set 4 cn — card grid, platforms first then features */
:root {
  --bg: #f3f4f6;
  --paper: #ffffff;
  --ink: #1f2933;
  --muted: #6b7280;
  --line: #e5e7eb;
  --brand: #e85d04;
  --brand-deep: #c24a00;
  --soft: #fff1e6;
  --sans: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
}

*,
*::before,
*::after { box-sizing: border-box; }
html { scroll-behavior: auto; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
}
img, svg { max-width: 100%; display: inline-block; vertical-align: middle; }
a { color: var(--brand-deep); }
.site-header { background: var(--paper); border-bottom: 1px solid var(--line); }
.site-header__inner,
.wrap { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.site-header__inner {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 800;
}
.brand svg { width: 28px; height: 28px; color: var(--brand); }
.site-nav { display: flex; gap: 8px; flex-wrap: wrap; }
.site-nav a {
  text-decoration: none;
  color: var(--ink);
  background: var(--bg);
  padding: 7px 12px;
  border-radius: 999px;
}
.site-nav a.is-active {
  background: var(--brand);
  color: #fff;
}
.hero-slim {
  padding: 28px 0 8px;
}
.hero-slim h1 { margin: 0 0 12px; font-size: 30px; line-height: 1.35; }
.hero-slim p { margin: 0 0 12px; color: var(--muted); }
.cta-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 14px 0 8px; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--brand);
  color: #fff;
  text-decoration: none;
  padding: 11px 18px;
  border-radius: 8px;
  font-weight: 700;
}
.btn:hover { background: var(--brand-deep); }
.btn-ghost {
  display: inline-flex;
  align-items: center;
  background: var(--paper);
  color: var(--brand-deep);
  border: 1px solid var(--brand);
  text-decoration: none;
  padding: 10px 16px;
  border-radius: 8px;
  font-weight: 700;
}
.grid-4, .grid-3, .grid-2 {
  display: grid;
  gap: 14px;
  margin: 8px 0 18px;
}
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
  box-shadow: 0 6px 16px rgba(31, 41, 51, 0.04);
}
.card h3 { margin: 8px 0 8px; font-size: 17px; }
.card p { margin: 0 0 10px; color: var(--muted); }
.card svg { width: 26px; height: 26px; color: var(--brand); }
section { padding: 18px 0 8px; }
section h2 { margin: 0 0 10px; font-size: 22px; }
section > p { margin: 0 0 12px; }
table { width: 100%; border-collapse: collapse; background: var(--paper); }
th, td { border: 1px solid var(--line); padding: 10px; text-align: left; vertical-align: top; }
th { background: var(--soft); }
.faq-item { background: var(--paper); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; margin: 0 0 10px; }
.faq-item h3 { margin: 0 0 8px; font-size: 16.5px; }
.site-footer {
  margin-top: 20px;
  background: var(--paper);
  border-top: 1px solid var(--line);
  padding: 18px 0 26px;
  color: var(--muted);
  font-size: 13.5px;
}
.site-footer p { margin: 0 0 8px; }
@media (max-width: 980px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 680px) {
  .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .site-header__inner { flex-direction: column; padding: 10px 0; }
  .hero-slim h1 { font-size: 26px; }
}