:root {
  --bg: #f5f5f7;
  --card: #ffffff;
  --text: #1d1d1f;
  --sub: #6e6e73;
  --blue: #0071e3;
  --line: #d2d2d7;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
header {
  background: rgba(255,255,255,.88);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 10;
}
.nav {
  max-width: 980px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 20px;
}
.brand { font-weight: 600; letter-spacing: -0.01em; }
.menu { display: flex; gap: 18px; font-size: 14px; color: var(--sub); }
.hero {
  max-width: 980px; margin: 56px auto 30px;
  padding: 0 20px; text-align: center;
}
.hero h1 { font-size: 48px; line-height: 1.08; margin: 0 0 12px; letter-spacing: -0.02em; }
.hero p { color: var(--sub); font-size: 21px; margin: 0 auto 24px; max-width: 760px; }
.cta { display: flex; justify-content: center; gap: 14px; flex-wrap: wrap; }
.btn {
  border-radius: 999px; padding: 10px 18px; font-weight: 500;
  border: 1px solid var(--blue); color: var(--blue); background: #fff;
}
.btn.primary { background: var(--blue); color: #fff; }
.wrap { max-width: 980px; margin: 26px auto 70px; padding: 0 20px; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit,minmax(240px,1fr)); }
.card {
  background: var(--card); border-radius: 20px;
  padding: 24px; border: 1px solid #ededf1;
}
.app-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}
.app-icon {
  width: 72px;
  height: 72px;
  border-radius: 16px;
  margin-bottom: 12px;
  box-shadow: 0 6px 16px rgba(0,0,0,.12);
}
.card h3 { margin: 0 0 10px; font-size: 20px; letter-spacing: -0.01em; }
.card p { margin: 0; color: var(--sub); font-size: 15px; }
.tag {
  display: inline-block;
  font-size: 12px;
  color: #285ea8;
  background: #eaf2ff;
  border: 1px solid #cfe1ff;
  border-radius: 999px;
  padding: 1px 8px;
  vertical-align: middle;
}
.legal {
  background: var(--card); border-radius: 20px; border: 1px solid #ededf1;
  padding: 28px;
}
.legal h1 { margin-top: 0; font-size: 36px; letter-spacing: -0.02em; }
.legal h2 { margin-top: 30px; font-size: 22px; letter-spacing: -0.01em; }
.legal p, .legal li { color: #424245; }
footer {
  border-top: 1px solid var(--line);
  color: var(--sub); font-size: 12px;
  max-width: 980px; margin: 0 auto; padding: 16px 20px 26px;
}
.beian-bottom {
  margin-top: 8px;
  color: #666;
}
.small { font-size: 13px; color: var(--sub); }
@media (max-width: 640px) {
  .hero h1 { font-size: 34px; }
  .hero p { font-size: 18px; }
}