:root {
  color-scheme: light;
  --ink: #17202b;
  --muted: #5f6b7a;
  --line: #dfe5ec;
  --blue: #1468e8;
  --blue-dark: #0c4fb8;
  --green: #087b53;
  --surface: #f4f7fa;
}

* { box-sizing: border-box; letter-spacing: 0; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
}
a { color: inherit; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 20px; font-size: clamp(38px, 5vw, 64px); line-height: 1.12; }
h2 { margin-bottom: 14px; font-size: 32px; line-height: 1.25; }

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1160px, calc(100% - 40px));
  height: 72px;
  margin: 0 auto;
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 700; }
.brand img { width: 32px; height: 32px; }
.header-link { color: var(--blue); text-decoration: none; font-size: 14px; }

.hero { overflow: hidden; background: var(--surface); border-block: 1px solid var(--line); }
.hero-inner, .section-inner { width: min(1160px, calc(100% - 40px)); margin: 0 auto; }
.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(420px, 1.1fr);
  align-items: center;
  gap: 72px;
  min-height: 610px;
  padding: 70px 0;
}
.eyebrow { margin: 0 0 12px; color: var(--green); font-size: 13px; font-weight: 700; }
.lead { max-width: 590px; margin-bottom: 28px; color: var(--muted); font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.primary-button, .secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid var(--blue);
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}
.primary-button { color: #fff; background: var(--blue); }
.primary-button:hover { background: var(--blue-dark); border-color: var(--blue-dark); }
.secondary-button { color: var(--blue); background: #fff; }
.compatibility { margin: 14px 0 0; color: #7c8796; font-size: 13px; }
.product-shot { margin: 0; }
.product-shot img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid #d8dee7;
  border-radius: 8px;
  box-shadow: 0 24px 60px rgba(29, 45, 64, .16);
}

.feature-band, .install-band, .download-band { padding: 88px 0; }
.section-heading { max-width: 680px; margin-bottom: 38px; }
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-block: 1px solid var(--line);
}
.feature-grid article { min-height: 235px; padding: 30px; border-right: 1px solid var(--line); }
.feature-grid article:last-child { border-right: 0; }
.feature-number { color: var(--blue); font-weight: 700; }
.feature-grid h3 { margin: 34px 0 10px; font-size: 19px; }
.feature-grid p, .download-inner p, .install-steps span, .policy-content p, .policy-content li { color: var(--muted); }

.install-band { color: #fff; background: #17202b; }
.install-layout { display: grid; grid-template-columns: .7fr 1.3fr; gap: 80px; }
.install-steps { display: grid; margin: 0; padding: 0; list-style: none; counter-reset: step; }
.install-steps li {
  display: grid;
  grid-template-columns: 48px 190px 1fr;
  gap: 20px;
  padding: 21px 0;
  border-top: 1px solid #394450;
  counter-increment: step;
}
.install-steps li::before { content: "0" counter(step); color: #75a9ff; font-weight: 700; }
.install-steps span { color: #b9c2cc; }

.download-band { background: var(--surface); }
.download-inner { display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.download-inner h2, .download-inner p { margin-bottom: 6px; }
.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1160px, calc(100% - 40px));
  min-height: 88px;
  margin: 0 auto;
  color: #7c8796;
  font-size: 13px;
}
.site-footer a { color: var(--blue); text-decoration: none; }

.policy-page { background: var(--surface); }
.policy-main { padding: 60px 20px 90px; border-top: 1px solid var(--line); }
.policy-content {
  width: min(820px, 100%);
  margin: 0 auto;
  padding: 54px 64px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.policy-content h1 { font-size: 42px; }
.policy-content h2 { margin-top: 38px; font-size: 21px; }
.policy-content ul { padding-left: 22px; }

@media (max-width: 820px) {
  .hero-inner { grid-template-columns: 1fr; gap: 42px; min-height: 0; padding: 58px 0; }
  .feature-grid, .install-layout { grid-template-columns: 1fr; }
  .feature-grid article { border-right: 0; border-bottom: 1px solid var(--line); }
  .feature-grid article:last-child { border-bottom: 0; }
  .install-layout { gap: 32px; }
}

@media (max-width: 560px) {
  .site-header, .hero-inner, .section-inner, .site-footer { width: min(100% - 28px, 1160px); }
  .site-header { height: 62px; }
  .brand span { max-width: 160px; line-height: 1.2; }
  .hero-inner { padding: 44px 0 50px; }
  h1 { font-size: 38px; }
  h2 { font-size: 27px; }
  .feature-band, .install-band, .download-band { padding: 62px 0; }
  .install-steps li { grid-template-columns: 1fr; gap: 6px; }
  .download-inner, .site-footer { align-items: flex-start; flex-direction: column; }
  .download-inner .primary-button { width: 100%; }
  .site-footer { justify-content: center; padding: 24px 0; }
  .policy-main { padding: 24px 14px 54px; }
  .policy-content { padding: 32px 22px; }
}