:root {
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --primary-soft: #eff6ff;
  --primary-line: #bfdbfe;
  --ink: #0f172a;
  --muted: #64748b;
  --muted-2: #94a3b8;
  --line: #e2e8f0;
  --line-soft: #eef2f7;
  --bg: #f5f7fa;
  --surface: #ffffff;
  --success: #0e9f6e;
  --warning: #d97706;
  --warning-soft: #fffbeb;
  --dark: #0f172a;
  --radius: 22px;
  --shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
  --container: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
::selection { background: var(--primary-line); color: var(--ink); }
:focus-visible { outline: 2px solid var(--primary); outline-offset: 3px; }

.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.icon {
  width: 1.15em;
  height: 1.15em;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.container { width: min(var(--container), calc(100% - 48px)); margin: 0 auto; }
.notice {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 10px 18px;
  background: var(--warning-soft);
  border-bottom: 1px solid #fde68a;
  color: #92400e;
  font-size: 13px;
  text-align: center;
}
.notice[hidden] { display: none; }
.notice button {
  border: 0;
  background: transparent;
  color: #92400e;
  font-weight: 650;
  cursor: pointer;
  padding: 4px 8px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line-soft);
}
.nav { height: 70px; display: flex; align-items: center; gap: 32px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 19px; font-weight: 750; letter-spacing: -0.02em; }
.brand-mark { width: 34px; height: 34px; border-radius: 9px; }
.nav-links { display: flex; align-items: center; gap: 28px; margin-left: 8px; color: var(--muted); font-size: 14px; font-weight: 550; }
.nav-links a:hover { color: var(--ink); }
.nav-cta {
  margin-left: auto;
  height: 38px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  background: var(--primary);
  color: #fff;
  font-size: 14px;
  font-weight: 650;
}
.nav-cta:hover { background: var(--primary-strong); }

.hero {
  position: relative;
  overflow: hidden;
  padding: 76px 0 64px;
  background: var(--bg);
  border-bottom: 1px solid var(--line-soft);
}
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center; }
.eyebrow {
  margin: 0 0 14px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}
.hero h1 {
  margin: 0;
  font-size: clamp(40px, 5.2vw, 64px);
  line-height: 1.08;
  letter-spacing: -0.045em;
  font-weight: 800;
}
.hero h1 span { color: var(--primary); }
.lead { max-width: 540px; margin: 22px 0 0; color: var(--muted); font-size: 17px; line-height: 1.8; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.hero-points { display: flex; flex-wrap: wrap; gap: 10px 22px; margin-top: 26px; color: var(--muted); font-size: 13px; }
.hero-points span { display: inline-flex; align-items: center; gap: 7px; }
.hero-points .icon { color: var(--primary); font-size: 15px; }

.btn {
  height: 52px;
  padding: 0 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border: 1px solid transparent;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 650;
  line-height: 1;
  cursor: pointer;
  transition: background 0.18s ease, border-color 0.18s ease, color 0.18s ease, transform 0.18s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-strong); }
.btn-ghost { background: var(--surface); border-color: var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--primary-line); color: var(--primary); }
.btn-dark { background: var(--dark); color: #fff; }
.btn-dark:hover { background: #1e293b; }
.btn-block { width: 100%; }
.js-download[aria-disabled="true"] { opacity: 0.55; pointer-events: none; }

.hero-visual { position: relative; min-height: 690px; display: flex; align-items: center; justify-content: center; }
.hero-shape { position: absolute; border-radius: 50%; z-index: 0; }
.hero-shape--one { width: 300px; height: 300px; top: 10px; left: -40px; background: #dbeafe; }
.hero-shape--two { width: 190px; height: 190px; right: -20px; bottom: 80px; background: #e0ecff; }
.phone {
  position: relative;
  z-index: 1;
  width: 300px;
  aspect-ratio: 430 / 932;
  padding: 0;
  border: 8px solid var(--dark);
  border-radius: 38px;
  background: var(--dark);
  box-shadow: 0 30px 70px rgba(15, 23, 42, 0.22);
  overflow: hidden;
}
.phone img { width: 100%; height: 100%; object-fit: cover; border-radius: 30px; }
.float-card {
  position: absolute;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 14px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.1);
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}
.float-card small { color: var(--muted); font-weight: 500; }
.float-card--version { top: 60px; left: -50px; }
.float-card--safe { right: -50px; bottom: 150px; color: var(--muted); font-weight: 550; }
.float-card--safe .icon { color: var(--primary); }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--success); box-shadow: 0 0 0 4px #dcfce7; }
.visual-caption { position: absolute; z-index: 2; bottom: -30px; left: 50%; transform: translateX(-50%); margin: 0; color: var(--muted-2); font-size: 12px; white-space: nowrap; }

.trust { background: var(--surface); border-bottom: 1px solid var(--line-soft); }
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; padding: 22px 0; }
.trust-grid div { display: flex; align-items: center; gap: 9px; color: var(--muted); font-size: 13px; }
.trust-grid .icon { color: var(--primary); font-size: 17px; }

.section { padding: 88px 0; scroll-margin-top: 88px; }
.section--soft { background: var(--bg); }
.section-head { max-width: 720px; margin-bottom: 38px; }
.section-head h2 { margin: 0; font-size: clamp(28px, 3.2vw, 38px); line-height: 1.2; letter-spacing: -0.035em; font-weight: 780; }
.section-head .eyebrow { margin-bottom: 10px; }
.section-head p:last-child { margin: 14px 0 0; color: var(--muted); font-size: 15px; }

.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.feature-card {
  padding: 26px 24px;
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: 20px;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}
.feature-card:hover { border-color: var(--primary-line); transform: translateY(-2px); box-shadow: 0 14px 34px rgba(15, 23, 42, 0.06); }
.feature-icon {
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 22px;
}
.feature-card h3 { margin: 18px 0 7px; font-size: 17px; font-weight: 700; }
.feature-card p { margin: 0; color: var(--muted); font-size: 13.5px; line-height: 1.7; }

.download-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: start; }
.download-card {
  padding: 32px;
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.04);
}
.download-card--android { border-color: var(--primary-line); }
.download-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 26px;
}
.download-card h3 { margin: 18px 0 6px; font-size: 23px; font-weight: 760; letter-spacing: -0.02em; }
.download-desc { margin: 0; color: var(--muted); font-size: 14px; }
.release-meta { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 12px; }
.pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  background: #f1f5f9;
  color: var(--muted);
  font-size: 12px;
  font-weight: 550;
}
.pill--primary { background: var(--primary-soft); color: var(--primary); }
.pill strong { font-weight: 750; }
.release-notes { min-height: 46px; margin: 0 0 18px; color: var(--muted); font-size: 13px; line-height: 1.7; }
.fine-print { margin: 13px 0 0; color: var(--muted-2); font-size: 12px; line-height: 1.6; }
.qr-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}
.qr-row small { color: var(--muted-2); font-size: 12px; }
.qr { width: 96px; height: 96px; padding: 4px; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.sha-box { margin-top: 18px; border-top: 1px solid var(--line-soft); padding-top: 14px; }
.sha-box summary { cursor: pointer; color: var(--muted); font-size: 12px; font-weight: 600; }
.sha-row { display: flex; align-items: flex-start; gap: 10px; margin-top: 10px; }
.sha-row code { flex: 1; word-break: break-all; color: var(--muted); font-size: 11px; line-height: 1.6; background: #f8fafc; border-radius: 8px; padding: 8px 10px; }
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  height: 30px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--muted);
  font-size: 12px;
  cursor: pointer;
  white-space: nowrap;
}
.copy-btn:hover { border-color: var(--primary-line); color: var(--primary); }
.ios-highlight { margin: 20px 0; padding: 18px; background: var(--primary-soft); border: 1px solid #dbeafe; border-radius: 16px; }
.ios-badge { display: inline-flex; align-items: center; gap: 7px; color: var(--primary); font-size: 13px; font-weight: 700; }
.ios-highlight p { margin: 8px 0 0; color: var(--muted); font-size: 13px; }

.install-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: start; }
.install-card { padding: 30px; background: var(--surface); border: 1px solid var(--line-soft); border-radius: var(--radius); }
.install-head { display: flex; align-items: center; gap: 14px; padding-bottom: 20px; border-bottom: 1px solid var(--line-soft); }
.install-icon { width: 46px; height: 46px; display: flex; align-items: center; justify-content: center; border-radius: 14px; background: var(--primary-soft); color: var(--primary); font-size: 23px; }
.install-head h3 { margin: 0; font-size: 19px; }
.install-head p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.step-list { list-style: none; margin: 22px 0 0; padding: 0; display: grid; gap: 18px; }
.step-list li { display: flex; gap: 14px; align-items: flex-start; }
.step-num { width: 28px; height: 28px; flex: 0 0 auto; display: inline-flex; align-items: center; justify-content: center; border-radius: 50%; background: var(--primary-soft); color: var(--primary); font-size: 12px; font-weight: 750; margin-top: 2px; }
.step-list strong { display: block; font-size: 14px; }
.step-list p { margin: 4px 0 0; color: var(--muted); font-size: 13px; line-height: 1.65; }
.tip { display: flex; gap: 9px; align-items: flex-start; margin-top: 22px; padding: 13px 14px; border-radius: 12px; background: var(--warning-soft); border: 1px solid #fde68a; color: #92400e; font-size: 12px; line-height: 1.65; }
.tip .icon { margin-top: 1px; font-size: 15px; }

.faq-wrap { max-width: 920px; }
.faq-list { display: grid; gap: 12px; }
.faq-list details { background: var(--surface); border: 1px solid var(--line-soft); border-radius: 16px; padding: 0 20px; }
.faq-list summary { position: relative; list-style: none; cursor: pointer; padding: 18px 34px 18px 0; font-size: 15px; font-weight: 650; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 0; top: 50%; transform: translateY(-50%); color: var(--muted-2); font-size: 20px; font-weight: 400; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list p { margin: -2px 0 18px; color: var(--muted); font-size: 13.5px; line-height: 1.75; }

.cta-band { background: var(--dark); color: #fff; padding: 56px 0; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.cta-inner h2 { margin: 0; font-size: 30px; letter-spacing: -0.03em; }
.cta-inner p { margin: 8px 0 0; color: #cbd5e1; font-size: 14px; }

.footer { background: var(--surface); border-top: 1px solid var(--line-soft); padding: 48px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 0.8fr 1.3fr; gap: 40px; }
.footer-brand p { max-width: 340px; margin: 14px 0 0; color: var(--muted); font-size: 13px; }
.footer-links { display: grid; align-content: start; gap: 10px; font-size: 13px; color: var(--muted); }
.footer-links a:hover { color: var(--primary); }
.footer-note p { margin: 0 0 8px; color: var(--muted); font-size: 13px; }
.placeholder { color: var(--muted-2) !important; border-bottom: 1px dashed var(--line); display: inline-block; }
.footer-bottom { display: flex; justify-content: space-between; gap: 16px; margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--line-soft); color: var(--muted-2); font-size: 12px; }

.mobile-bar { display: none; }
.toast {
  position: fixed;
  left: 50%;
  bottom: 96px;
  z-index: 100;
  transform: translate(-50%, 10px);
  padding: 10px 16px;
  border-radius: 10px;
  background: var(--dark);
  color: #fff;
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 1100px) {
  .float-card { display: none; }
}

@media (max-width: 1024px) {
  .hero-grid { gap: 30px; }
  .hero-visual { min-height: 630px; }
  .phone { width: 270px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 900px) {
  .hero { padding: 56px 0 54px; }
  .hero-grid { grid-template-columns: 1fr; gap: 44px; }
  .hero-copy { max-width: 680px; }
  .hero-visual { min-height: 590px; }
  .phone { width: 260px; }
  .visual-caption { bottom: -18px; }
  .download-grid, .install-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 760px) {
  .container { width: min(var(--container), calc(100% - 32px)); }
  body { padding-bottom: 84px; }
  .nav { height: 62px; gap: 16px; }
  .nav-links { display: none; }
  .nav-cta { height: 34px; padding: 0 14px; font-size: 13px; }
  .brand { font-size: 18px; }
  .brand-mark { width: 30px; height: 30px; }
  .hero { padding: 42px 0 46px; }
  .hero h1 { font-size: clamp(36px, 10.5vw, 48px); }
  .lead { margin-top: 16px; font-size: 15.5px; }
  .hero-actions { margin-top: 24px; }
  .hero-actions .btn { flex: 1 1 auto; }
  .hero-points { gap: 8px 16px; font-size: 12.5px; }
  .hero-visual { min-height: 560px; }
  .phone { width: 244px; border-width: 7px; border-radius: 34px; }
  .phone img { border-radius: 27px; }
  .float-card { display: none; }
  .hero-shape--one { width: 230px; height: 230px; left: -80px; }
  .hero-shape--two { width: 150px; height: 150px; right: -50px; }
  .visual-caption { bottom: 4px; }
  .trust-grid { grid-template-columns: 1fr 1fr; gap: 14px; padding: 18px 0; }
  .trust-grid div { font-size: 12px; }
  .section { padding: 60px 0; }
  .section-head { margin-bottom: 28px; }
  .section-head h2 { font-size: 28px; }
  .feature-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
  .feature-card { padding: 20px 18px; border-radius: 16px; }
  .feature-icon { width: 40px; height: 40px; border-radius: 12px; font-size: 20px; }
  .feature-card h3 { margin-top: 14px; font-size: 15.5px; }
  .feature-card p { font-size: 12.5px; }
  .download-card, .install-card { padding: 24px 20px; border-radius: 18px; }
  .download-card h3 { font-size: 21px; }
  .qr { width: 84px; height: 84px; }
  .cta-inner { flex-direction: column; align-items: flex-start; }
  .cta-inner h2 { font-size: 26px; }
  .footer { padding-top: 36px; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .footer-brand { grid-column: auto; }
  .footer-bottom { flex-direction: column; gap: 6px; }
  .mobile-bar {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 60;
    display: flex;
    gap: 10px;
    padding: 10px 14px calc(10px + env(safe-area-inset-bottom));
    background: rgba(255, 255, 255, 0.97);
    border-top: 1px solid var(--line-soft);
  }
  .mobile-bar .btn { flex: 1; height: 48px; padding: 0 12px; font-size: 14px; }
}

@media (max-width: 380px) {
  .feature-grid { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}