:root {
  --blue: #087ee6;
  --blue-dark: #075fb4;
  --ink: #172033;
  --muted: #687386;
  --line: #e7edf5;
  --soft: #f5f9ff;
  --white: #fff;
  --warning: #fff8e7;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--white); font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif; }
a { color: var(--blue-dark); text-decoration: none; }
img { display: block; max-width: 100%; }
.container { width: min(1080px, calc(100% - 32px)); margin: 0 auto; }
.site-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid rgba(231,237,245,.9); background: rgba(255,255,255,.94); backdrop-filter: blur(14px); }
.nav { min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 11px; color: var(--ink); font-weight: 800; }
.brand img { width: 42px; height: 42px; border-radius: 12px; }
.nav-links { display: flex; gap: 24px; font-size: 14px; }
.hero { padding: 72px 0 58px; background: radial-gradient(circle at 85% 15%, #d8efff 0, transparent 34%), linear-gradient(180deg,#f8fcff,#fff); }
.hero-grid { display: grid; grid-template-columns: 1.35fr .65fr; align-items: center; gap: 54px; }
.eyebrow { color: var(--blue-dark); font-weight: 750; letter-spacing: .06em; }
h1 { max-width: 760px; margin: 10px 0 16px; font-size: clamp(36px,6vw,62px); line-height: 1.08; letter-spacing: -.04em; }
h2 { margin: 0 0 18px; font-size: clamp(25px,4vw,34px); line-height: 1.25; }
h3 { margin: 0 0 8px; font-size: 18px; }
.lead { max-width: 720px; color: var(--muted); font-size: 18px; }
.hero-logo { width: min(290px, 80vw); margin: auto; border-radius: 28%; box-shadow: 0 28px 70px rgba(8,126,230,.25); }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; padding: 0 24px; border-radius: 12px; background: var(--blue); color: var(--white); font-weight: 750; box-shadow: 0 10px 24px rgba(8,126,230,.2); }
.button.secondary { border: 1px solid var(--line); background: var(--white); color: var(--ink); box-shadow: none; }
.meta { display: flex; flex-wrap: wrap; gap: 10px 20px; margin-top: 22px; color: var(--muted); font-size: 14px; }
.section { padding: 64px 0; }
.section.soft { background: var(--soft); }
.section-intro { max-width: 720px; margin-bottom: 28px; color: var(--muted); }
.cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
.card { padding: 24px; border: 1px solid var(--line); border-radius: 18px; background: var(--white); box-shadow: 0 12px 38px rgba(39,74,120,.06); }
.card p { margin: 0; color: var(--muted); }
.steps { counter-reset: step; display: grid; gap: 16px; }
.step { position: relative; padding: 20px 22px 20px 68px; border: 1px solid var(--line); border-radius: 16px; }
.step::before { counter-increment: step; content: counter(step); position: absolute; top: 18px; left: 20px; width: 32px; height: 32px; display: grid; place-items: center; border-radius: 50%; background: var(--blue); color: white; font-weight: 800; }
.notice { padding: 18px 20px; border: 1px solid #f2d58a; border-radius: 14px; background: var(--warning); color: #644b09; }
.article { width: min(820px, calc(100% - 32px)); margin: auto; padding: 52px 0 90px; }
.article h1 { font-size: clamp(32px,5vw,48px); }
.article h2 { margin-top: 38px; font-size: 25px; }
.article p, .article li { color: #4b5668; }
.breadcrumbs { margin-bottom: 20px; color: var(--muted); font-size: 14px; }
.related { display: grid; grid-template-columns: repeat(2,1fr); gap: 12px; margin-top: 30px; }
.related a { padding: 15px 17px; border: 1px solid var(--line); border-radius: 12px; font-weight: 650; }
.site-footer { padding: 34px 0 94px; border-top: 1px solid var(--line); background: #101827; color: #c7d0df; }
.site-footer strong { display: block; margin-bottom: 6px; color: white; font-size: 17px; }
.site-footer p { margin: 6px 0; }
.sticky-download { position: fixed; z-index: 30; right: 18px; bottom: 18px; }
.sticky-download .button { min-width: 168px; }
.button-reset { border: 0; cursor: pointer; font: inherit; }
.download-dialog { width: min(560px, calc(100% - 28px)); padding: 0; border: 0; border-radius: 22px; box-shadow: 0 28px 90px rgba(12,31,61,.3); }
.download-dialog::backdrop { background: rgba(8,18,34,.68); backdrop-filter: blur(4px); }
.dialog-inner { position: relative; padding: 30px; text-align: center; }
.dialog-close { position: absolute; top: 14px; right: 14px; width: 38px; height: 38px; border: 0; border-radius: 50%; background: var(--soft); color: var(--ink); cursor: pointer; font-size: 24px; line-height: 1; }
.dialog-inner h2 { margin: 4px 34px 8px; }
.dialog-intro { margin: 0 0 18px; color: var(--muted); }
.qr-image { width: auto; max-width: min(300px, 78vw); height: auto; max-height: 46vh; margin: 0 auto; object-fit: contain; }
.dialog-tip { margin: 14px 0 20px; color: var(--muted); font-size: 14px; }
.dialog-actions { display: flex; align-items: center; justify-content: flex-end; gap: 14px; padding-top: 18px; border-top: 1px solid var(--line); }
.direct-download { font-size: 14px; font-weight: 700; }

@media (max-width: 760px) {
  body { padding-bottom: 76px; }
  .nav { min-height: 60px; }
  .brand img { width: 36px; height: 36px; }
  .nav-links { display: none; }
  .hero { padding: 46px 0 42px; }
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .hero-logo { width: 180px; }
  .cards, .related { grid-template-columns: 1fr; }
  .section { padding: 48px 0; }
  .sticky-download { left: 0; right: 0; bottom: 0; padding: 10px 16px calc(10px + env(safe-area-inset-bottom)); border-top: 1px solid var(--line); background: rgba(255,255,255,.96); }
  .sticky-download .button { width: 100%; }
  .site-footer { padding-bottom: 32px; }
  .dialog-inner { padding: 26px 18px 20px; }
  .dialog-actions { justify-content: center; }
}