:root {
  --brand: #1677ff;
  --brand-dark: #075fdb;
  --brand-soft: #eaf3ff;
  --ink: #162033;
  --muted: #667085;
  --line: #e7ebf2;
  --surface: #f6f9fd;
  --white: #fff;
  --shadow: 0 18px 60px rgba(30, 72, 130, .12);
  --radius: 22px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
img { display: block; max-width: 100%; }

.container { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid rgba(231, 235, 242, .8);
  background: rgba(255, 255, 255, .88);
  backdrop-filter: blur(18px);
}
.nav { min-height: 68px; display: flex; align-items: center; gap: 34px; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 21px; font-weight: 800; }
.logo-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 11px;
  color: #fff;
  background: linear-gradient(135deg, #35a5ff, #126cff);
  box-shadow: 0 8px 20px rgba(22, 119, 255, .25);
}
.nav-links { display: flex; align-items: center; gap: 28px; margin-right: auto; color: #475467; }
.nav-links a:hover, .nav-links a.active { color: var(--brand); }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.menu-btn { display: none; padding: 8px; border: 0; background: transparent; font-size: 24px; }
.btn {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 650;
  transition: .22s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { color: #fff; background: linear-gradient(135deg, #1989ff, #1265ed); box-shadow: 0 10px 24px rgba(22, 119, 255, .24); }
.btn-secondary { border-color: #cfd8e6; color: #344054; background: #fff; }
.btn-light { color: var(--brand); background: #fff; }
.btn-sm { min-height: 40px; padding: 0 17px; border-radius: 10px; font-size: 14px; }

.hero {
  position: relative;
  overflow: hidden;
  padding: 84px 0 76px;
  background:
    radial-gradient(circle at 80% 15%, rgba(90, 183, 255, .20), transparent 28%),
    radial-gradient(circle at 8% 80%, rgba(85, 226, 209, .15), transparent 25%),
    linear-gradient(180deg, #f7fbff 0%, #fff 100%);
}
.hero::before {
  position: absolute;
  inset: 0;
  content: "";
  opacity: .25;
  background-image: linear-gradient(#dce9f8 1px, transparent 1px), linear-gradient(90deg, #dce9f8 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(to bottom, #000, transparent 85%);
}
.hero-grid { position: relative; display: grid; grid-template-columns: 1.02fr .98fr; align-items: center; gap: 60px; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid #cfe3ff;
  border-radius: 999px;
  color: var(--brand-dark);
  background: rgba(255,255,255,.78);
  font-size: 13px;
  font-weight: 700;
}
.pulse { width: 7px; height: 7px; border-radius: 50%; background: #19b37a; box-shadow: 0 0 0 5px rgba(25,179,122,.12); }
h1 { margin: 22px 0 18px; font-size: clamp(42px, 5.4vw, 68px); line-height: 1.08; letter-spacing: -.045em; }
.gradient-text { color: transparent; background: linear-gradient(100deg, #0f6df4, #3aa4ff); background-clip: text; }
.hero-copy { max-width: 610px; margin: 0 0 30px; color: var(--muted); font-size: 18px; line-height: 1.8; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 13px; }
.requirements { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 18px; color: #7b8495; font-size: 13px; }
.visual-shell { position: relative; padding: 12px; border: 1px solid rgba(255,255,255,.92); border-radius: 26px; background: rgba(255,255,255,.65); box-shadow: var(--shadow); }
.visual-shell img { width: 100%; min-height: 360px; object-fit: cover; border-radius: 18px; background: linear-gradient(135deg, #e6f2ff, #f5fbff); }
.float-card {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 15px;
  border: 1px solid rgba(255,255,255,.9);
  border-radius: 14px;
  background: rgba(255,255,255,.92);
  box-shadow: 0 12px 30px rgba(41, 80, 130, .14);
  font-size: 13px;
  font-weight: 650;
}
.float-card.one { top: 14%; left: -38px; }
.float-card.two { right: -28px; bottom: 13%; }
.float-icon { display: grid; width: 34px; height: 34px; place-items: center; border-radius: 10px; color: var(--brand); background: var(--brand-soft); }

section { padding: 92px 0; }
.section-soft { background: var(--surface); }
.section-head { max-width: 720px; margin: 0 auto 44px; text-align: center; }
.section-head.left { margin-left: 0; text-align: left; }
.section-kicker { margin-bottom: 10px; color: var(--brand); font-size: 14px; font-weight: 750; letter-spacing: .08em; text-transform: uppercase; }
h2 { margin: 0 0 14px; font-size: clamp(30px, 4vw, 44px); line-height: 1.2; letter-spacing: -.025em; }
.section-head p, .lead { margin: 0; color: var(--muted); font-size: 17px; line-height: 1.8; }

.download-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.download-card, .feature-card, .news-card, .help-card, .solution-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  transition: .25s ease;
}
.download-card:hover, .feature-card:hover, .news-card:hover, .help-card:hover { transform: translateY(-6px); border-color: #bdd8ff; box-shadow: var(--shadow); }
.download-card { padding: 25px; }
.os-icon { display: grid; width: 52px; height: 52px; place-items: center; margin-bottom: 22px; border-radius: 15px; color: var(--brand); background: var(--brand-soft); font-size: 23px; font-weight: 800; }
.download-card h3 { margin: 0 0 7px; font-size: 21px; }
.download-card .sub { min-height: 42px; color: var(--muted); font-size: 14px; line-height: 1.5; }
.meta-list { margin: 18px 0; padding: 16px 0; border-block: 1px solid var(--line); color: #667085; font-size: 13px; line-height: 2; }
.meta-list b { float: right; color: #344054; font-weight: 600; }
.download-card .btn { width: 100%; }

.identity-switch { display: flex; justify-content: center; gap: 9px; margin: -20px 0 35px; }
.identity-switch button { padding: 9px 16px; border: 1px solid var(--line); border-radius: 999px; color: #667085; background: #fff; cursor: pointer; }
.identity-switch button.active { border-color: var(--brand); color: #fff; background: var(--brand); }
.ai-message { max-width: 800px; margin: 0 auto 36px; padding: 18px 22px; border: 1px solid #d8e8ff; border-radius: 16px; color: #3c506b; background: linear-gradient(90deg, #f1f7ff, #fbfdff); text-align: center; }

.feature-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; }
.feature-card { padding: 25px 20px; }
.feature-icon { display: grid; width: 46px; height: 46px; place-items: center; margin-bottom: 19px; border-radius: 14px; color: var(--brand); background: var(--brand-soft); font-size: 21px; }
.feature-card h3 { margin: 0 0 9px; font-size: 17px; }
.feature-card p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }

.solution-row { display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: 68px; }
.solution-row + .solution-row { margin-top: 80px; }
.solution-row.reverse .solution-copy { order: 2; }
.solution-row.reverse .solution-visual { order: 1; }
.solution-copy h2 { font-size: 38px; }
.solution-copy p { color: var(--muted); line-height: 1.9; }
.check-list { display: grid; gap: 13px; margin: 25px 0 30px; padding: 0; list-style: none; }
.check-list li { display: flex; gap: 10px; align-items: center; }
.check { display: grid; width: 22px; height: 22px; place-items: center; border-radius: 50%; color: var(--brand); background: var(--brand-soft); font-size: 12px; }
.solution-visual { padding: 12px; border: 1px solid var(--line); border-radius: 25px; background: #fff; box-shadow: var(--shadow); }
.solution-visual img { width: 100%; min-height: 340px; object-fit: cover; border-radius: 17px; background: #eef5fd; }

.trust { padding: 70px 0; border-block: 1px solid var(--line); }
.trust-number { margin-bottom: 34px; text-align: center; font-size: 24px; font-weight: 750; }
.trust-number strong { color: var(--brand); font-size: 38px; }
.brand-row { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.brand-item { padding: 20px 10px; border-radius: 14px; color: #5d6878; background: #f7f9fc; text-align: center; font-size: 19px; font-weight: 750; }

.news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.news-card { overflow: hidden; }
.news-card img { width: 100%; height: 190px; object-fit: cover; background: #e8f2ff; }
.news-body { padding: 23px; }
.news-tag { color: var(--brand); font-size: 13px; font-weight: 700; }
.news-card h3 { margin: 10px 0; font-size: 18px; line-height: 1.55; }
.news-card p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }

.faq-wrap { max-width: 900px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-question { display: flex; width: 100%; justify-content: space-between; padding: 22px 0; border: 0; color: var(--ink); background: transparent; text-align: left; cursor: pointer; font-size: 17px; font-weight: 650; }
.faq-answer { display: none; padding: 0 40px 22px 0; color: var(--muted); line-height: 1.8; }
.faq-item.open .faq-answer { display: block; }
.faq-item.open .plus { transform: rotate(45deg); }
.plus { color: var(--brand); font-size: 24px; transition: .2s; }

.page-hero { padding: 74px 0 62px; background: linear-gradient(180deg, #f3f8ff, #fff); text-align: center; }
.page-hero h1 { font-size: clamp(38px, 5vw, 56px); }
.page-hero p { max-width: 680px; margin: 0 auto; color: var(--muted); font-size: 17px; line-height: 1.8; }
.platform-detail { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.platform-panel { display: flex; gap: 22px; padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); }
.platform-panel .os-icon { flex: 0 0 52px; margin: 0; }
.platform-panel h3 { margin: 2px 0 7px; }
.platform-panel p { margin: 0 0 17px; color: var(--muted); font-size: 14px; line-height: 1.7; }
.help-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.help-card { padding: 26px; }
.help-card h3 { margin: 13px 0 8px; }
.help-card p { color: var(--muted); font-size: 14px; line-height: 1.7; }
.search-box { display: flex; max-width: 620px; margin: 30px auto 0; padding: 7px; border: 1px solid #cfe0f6; border-radius: 14px; background: #fff; box-shadow: 0 10px 35px rgba(29,83,148,.08); }
.search-box input { flex: 1; min-width: 0; padding: 0 14px; border: 0; outline: 0; }

.cta-section { padding: 82px 0; }
.cta-box { position: relative; overflow: hidden; padding: 58px; border-radius: 30px; color: #fff; background: linear-gradient(120deg, #0b6bf2, #26a4ff); }
.cta-box::after { position: absolute; width: 320px; height: 320px; right: -70px; top: -150px; border: 60px solid rgba(255,255,255,.1); border-radius: 50%; content: ""; }
.cta-box h2 { position: relative; margin-bottom: 12px; }
.cta-box p { position: relative; color: rgba(255,255,255,.85); }
.cta-benefits { position: relative; display: flex; flex-wrap: wrap; gap: 22px; margin: 24px 0 30px; color: rgba(255,255,255,.92); font-size: 14px; }

footer { padding: 55px 0 30px; color: #98a2b3; background: #101828; }
.footer-grid { display: grid; grid-template-columns: 1.5fr repeat(3, 1fr); gap: 40px; }
.footer-brand p { max-width: 330px; font-size: 14px; line-height: 1.8; }
.footer-title { margin-bottom: 17px; color: #fff; font-weight: 700; }
.footer-links { display: grid; gap: 11px; font-size: 14px; }
.footer-links a:hover { color: #fff; }
.copyright { margin-top: 40px; padding-top: 24px; border-top: 1px solid #273244; font-size: 13px; }
.reveal { opacity: 0; transform: translateY(20px); transition: .65s ease; }
.reveal.visible { opacity: 1; transform: none; }

@media (max-width: 960px) {
  .nav-links { display: none; position: absolute; top: 68px; left: 0; right: 0; padding: 20px; border-bottom: 1px solid var(--line); background: #fff; }
  .nav-links.open { display: grid; }
  .menu-btn { display: block; margin-left: auto; }
  .nav-actions .btn-secondary { display: none; }
  .hero-grid, .solution-row { grid-template-columns: 1fr; }
  .hero-grid { gap: 45px; }
  .visual-shell { max-width: 680px; }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .solution-row.reverse .solution-copy, .solution-row.reverse .solution-visual { order: initial; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .container { width: min(100% - 28px, 1180px); }
  section { padding: 68px 0; }
  .nav-actions .btn-primary { display: none; }
  .hero { padding: 60px 0 55px; }
  h1 { font-size: 42px; }
  .hero-copy { font-size: 16px; }
  .hero-actions .btn { width: 100%; }
  .float-card { display: none; }
  .visual-shell img { min-height: 230px; }
  .download-grid, .feature-grid, .news-grid, .platform-detail, .help-grid, .brand-row { grid-template-columns: 1fr; }
  .identity-switch { flex-wrap: wrap; }
  .brand-row { grid-template-columns: repeat(2, 1fr); }
  .solution-row { gap: 35px; }
  .solution-visual img { min-height: 230px; }
  .cta-box { padding: 38px 24px; }
  .footer-grid { grid-template-columns: 1fr; }
}