:root {
  --blue: #1976d2;
  --blue-dark: #0d5fb4;
  --blue-soft: #eaf4ff;
  --teal: #168f84;
  --green: #2f9e58;
  --amber: #b96c00;
  --ink: #172033;
  --muted: #5f6b7a;
  --line: #dbe3ec;
  --surface: #ffffff;
  --canvas: #f7f9fc;
  --soft: #eef4f9;
  --shadow: 0 18px 48px rgba(39, 72, 108, 0.12);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --shell: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
body:has(dialog[open]) { overflow: hidden; }
a { color: inherit; }
img { display: block; max-width: 100%; }
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
.shell { width: min(var(--shell), calc(100% - 40px)); margin: 0 auto; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 1000; padding: 10px 14px; color: #fff; background: var(--blue); border-radius: 8px; }
.skip-link:focus { top: 12px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(219, 227, 236, .84);
  background: rgba(247, 249, 252, .9);
  backdrop-filter: blur(18px);
}
.nav-wrap { min-height: 72px; display: flex; align-items: center; gap: 32px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 760; text-decoration: none; letter-spacing: -.01em; }
.app-mark { position: relative; display: inline-block; width: 58px; height: 58px; flex: 0 0 auto; border-radius: 17px; background: var(--blue); box-shadow: 0 12px 26px rgba(25, 118, 210, .24); }
.app-mark::before { content: ""; position: absolute; left: 21px; top: 17px; border-top: 12px solid transparent; border-bottom: 12px solid transparent; border-left: 17px solid #fff; }
.app-mark i { position: absolute; width: 4px; height: 25px; right: 15px; top: 17px; border-radius: 2px; background: #fff; }
.app-mark b { display: none; }
.app-mark--small { width: 34px; height: 34px; border-radius: 10px; box-shadow: none; }
.app-mark--small::before { left: 12px; top: 10px; border-top-width: 7px; border-bottom-width: 7px; border-left-width: 10px; }
.app-mark--small i { width: 3px; height: 15px; right: 8px; top: 10px; }
.nav-links { margin-left: auto; display: flex; align-items: center; gap: 28px; }
.nav-links a { color: var(--muted); font-size: 14px; text-decoration: none; }
.nav-links a:hover { color: var(--blue); }

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 44px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 12px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: transform .2s ease, background .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.button:hover { transform: translateY(-2px); }
.button--primary { color: #fff; background: var(--blue); box-shadow: 0 10px 24px rgba(25, 118, 210, .2); }
.button--primary:hover { background: var(--blue-dark); box-shadow: 0 14px 30px rgba(25, 118, 210, .25); }
.button--ghost { color: var(--ink); background: var(--surface); border-color: var(--line); }
.button--ghost:hover { border-color: #a9bfd5; }
.button--small { min-height: 38px; padding: 0 17px; font-size: 14px; color: #fff; background: var(--blue); }
.button--large { min-height: 54px; padding: 0 28px; }

.hero { position: relative; overflow: hidden; padding: 92px 0 100px; background: radial-gradient(circle at 86% 20%, #dceeff 0, rgba(220,238,255,0) 36%), var(--canvas); }
.hero::after { content: ""; position: absolute; width: 360px; height: 360px; left: -210px; bottom: -250px; border: 72px solid rgba(25,118,210,.05); border-radius: 50%; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(390px, .95fr); align-items: center; gap: 76px; }
.hero-copy { position: relative; z-index: 1; }
.eyebrow, .section-kicker { color: var(--blue); font-size: 13px; font-weight: 760; letter-spacing: .11em; text-transform: uppercase; }
.eyebrow { display: inline-flex; align-items: center; gap: 9px; margin-bottom: 24px; padding: 7px 12px; border: 1px solid #cce2f7; border-radius: 999px; background: rgba(255,255,255,.72); }
.eyebrow span { width: 7px; height: 7px; background: var(--green); border-radius: 50%; box-shadow: 0 0 0 4px rgba(47,158,88,.11); }
.hero h1 { margin: 0; max-width: 680px; font-size: clamp(48px, 6.2vw, 78px); line-height: 1.08; letter-spacing: -.055em; }
.hero h1 em { color: var(--blue); font-style: normal; }
.hero-lead { max-width: 620px; margin: 26px 0 32px; color: var(--muted); font-size: clamp(17px, 2vw, 20px); }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.release-facts { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 25px; }
.release-facts span { padding: 6px 11px; color: #496071; font-size: 13px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255,255,255,.7); }
.device-note { max-width: 620px; margin: 14px 0 0; color: #778393; font-size: 13px; }
.download-fallback { max-width: 620px; display: flex; align-items: center; gap: 10px; margin-top: 10px; color: #66788b; font-size: 12px; }
.download-fallback button { padding: 3px 0; color: var(--blue); border: 0; border-bottom: 1px solid rgba(25,118,210,.34); background: transparent; cursor: pointer; white-space: nowrap; }
.download-fallback.is-warning { padding: 11px 13px; color: #765b36; border: 1px solid #f0cc98; border-radius: 10px; background: #fff8ed; }

.product-stage { position: relative; min-height: 620px; display: grid; place-items: center; }
.phone-shot { position: relative; z-index: 2; width: 294px; padding: 11px; border: 1px solid #253349; border-radius: 40px; background: #111927; box-shadow: 0 38px 80px rgba(25, 50, 83, .24), 0 0 0 7px rgba(255,255,255,.76); transform: rotate(2deg); }
.phone-shot img { width: 100%; height: auto; aspect-ratio: 1080 / 2244; object-fit: cover; object-position: top; border-radius: 30px; }
.phone-speaker { position: absolute; z-index: 3; width: 68px; height: 19px; left: 50%; top: 7px; transform: translateX(-50%); border-radius: 0 0 12px 12px; background: #111927; }
.status-note { position: absolute; z-index: 3; min-width: 205px; display: flex; align-items: center; gap: 11px; padding: 13px 16px; border: 1px solid rgba(197,214,231,.9); border-radius: 16px; background: rgba(255,255,255,.94); box-shadow: var(--shadow); }
.status-note strong, .status-note small { display: block; }
.status-note strong { font-size: 13px; }
.status-note small { margin-top: 2px; color: var(--muted); font-size: 11px; }
.status-note--top { top: 104px; left: 0; }
.status-note--bottom { right: -6px; bottom: 90px; }
.status-dot { width: 11px; height: 11px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px rgba(47,158,88,.12); }
.privacy-glyph { width: 25px; height: 25px; display: grid; place-items: center; color: #fff; border-radius: 8px; background: var(--blue); font-weight: 800; }

.trust-strip { border-block: 1px solid var(--line); background: var(--surface); }
.trust-grid { display: grid; grid-template-columns: repeat(3, 1fr); }
.trust-grid > div { display: grid; grid-template-columns: 36px 1fr; column-gap: 12px; padding: 26px 30px; }
.trust-grid > div + div { border-left: 1px solid var(--line); }
.trust-grid span { grid-row: 1 / 3; color: var(--blue); font-size: 22px; }
.trust-grid strong, .trust-grid small { display: block; }
.trust-grid strong { font-size: 14px; }
.trust-grid small { color: var(--muted); font-size: 12px; }

.section { padding: 104px 0; }
.section--soft { border-block: 1px solid var(--line); background: var(--soft); }
.section-heading { max-width: 700px; margin: 0 auto 50px; text-align: center; }
.section-heading--left { margin-left: 0; text-align: left; }
.section-heading h2 { margin: 8px 0 14px; font-size: clamp(34px, 4vw, 50px); line-height: 1.16; letter-spacing: -.04em; }
.section-heading > p:last-child { margin: 0; color: var(--muted); font-size: 16px; }
.section-kicker { margin: 0; }

.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feature-card { min-height: 230px; padding: 28px; border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--surface); }
.feature-card--wide { grid-column: span 2; }
.feature-card--accent { color: #fff; border-color: var(--blue); background: var(--blue); }
.feature-card h3 { margin: 45px 0 8px; font-size: 21px; letter-spacing: -.02em; }
.feature-card p { margin: 0; color: var(--muted); font-size: 14px; }
.feature-card--accent p { color: rgba(255,255,255,.82); }
.feature-index { display: inline-flex; min-width: 40px; padding-bottom: 8px; color: var(--blue); border-bottom: 2px solid currentColor; font-size: 13px; font-weight: 800; }
.feature-card--accent .feature-index { color: #fff; }

.permission-list { overflow: hidden; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--surface); }
.permission-list details + details { border-top: 1px solid var(--line); }
.permission-list summary { display: grid; grid-template-columns: 54px 1fr auto; align-items: center; gap: 16px; padding: 23px 26px; cursor: pointer; list-style: none; }
.permission-list summary::-webkit-details-marker { display: none; }
.permission-list summary strong, .permission-list summary small { display: block; }
.permission-list summary strong { font-size: 16px; }
.permission-list summary small { margin-top: 2px; color: var(--muted); font-size: 12px; }
.permission-list summary b { color: var(--blue); font-size: 12px; }
.permission-number { width: 42px; height: 42px; display: grid; place-items: center; color: var(--blue); border-radius: 12px; background: var(--blue-soft); font-size: 12px; font-weight: 800; }
.permission-body { padding: 0 26px 24px 96px; color: var(--muted); }
.permission-body p { margin: 7px 0; }
.permission-body strong { color: var(--ink); }
.privacy-proof { display: flex; gap: 16px; align-items: flex-start; margin-top: 20px; padding: 22px 25px; color: #174c31; border: 1px solid #bde4cc; border-radius: var(--radius-md); background: #eefaf2; }
.privacy-proof > span { width: 28px; height: 28px; display: grid; place-items: center; flex: 0 0 auto; color: #fff; border-radius: 50%; background: var(--green); font-weight: 800; }
.privacy-proof strong { display: block; }
.privacy-proof p { margin: 4px 0 0; color: #4b6f59; font-size: 13px; }

.install-prelude { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-bottom: 34px; }
.install-prelude > div { display: flex; gap: 13px; padding: 18px; border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--surface); }
.install-prelude span { width: 30px; height: 30px; display: grid; place-items: center; flex: 0 0 auto; color: #fff; border-radius: 9px; background: var(--ink); font-size: 12px; font-weight: 800; }
.install-prelude p { margin: 0; }
.install-prelude strong, .install-prelude small { display: block; }
.install-prelude small { margin-top: 4px; color: var(--muted); font-size: 12px; line-height: 1.55; }
.guide-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.guide-card { overflow: hidden; display: grid; grid-template-columns: 1fr 214px; min-height: 430px; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--surface); }
.guide-card--last { grid-column: 1 / -1; grid-template-columns: 1fr 260px; }
.guide-copy { padding: 29px 26px; }
.guide-copy > span { color: var(--blue); font-size: 12px; font-weight: 800; letter-spacing: .08em; }
.guide-copy h3 { margin: 13px 0 8px; font-size: 22px; line-height: 1.3; }
.guide-copy p { margin: 0; color: var(--muted); font-size: 14px; }
.image-button { overflow: hidden; padding: 0; border: 0; border-left: 1px solid var(--line); background: #f2f6fa; cursor: zoom-in; }
.image-button img { width: 100%; height: 100%; object-fit: cover; object-position: top; transition: transform .35s ease; }
.image-button:hover img { transform: scale(1.025); }
.risk-callout { display: flex; align-items: flex-start; gap: 18px; margin-top: 22px; padding: 24px 26px; border: 1px solid #f0cc98; border-radius: var(--radius-md); background: #fff8ed; }
.risk-icon { width: 34px; height: 34px; display: grid; place-items: center; flex: 0 0 auto; color: #fff; border-radius: 10px; background: var(--amber); font-weight: 900; }
.risk-callout h3 { margin: 1px 0 5px; font-size: 16px; }
.risk-callout p { margin: 0; color: #765b36; font-size: 13px; }

.faq-layout { display: grid; grid-template-columns: .72fr 1.28fr; gap: 80px; align-items: start; }
.faq-intro { position: sticky; top: 110px; }
.faq-list { overflow: hidden; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { display: flex; justify-content: space-between; gap: 18px; padding: 22px 2px; cursor: pointer; list-style: none; font-weight: 700; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary span { color: var(--blue); font-size: 20px; font-weight: 400; }
.faq-list details[open] summary span { transform: rotate(45deg); }
.faq-list details p { margin: -6px 0 24px; padding-right: 46px; color: var(--muted); font-size: 14px; }

.feedback-section { background: var(--surface); }
.feedback-card { display: grid; grid-template-columns: 1.08fr .92fr; gap: 46px; align-items: center; padding: 46px; border: 1px solid #cfe1f2; border-radius: var(--radius-lg); background: linear-gradient(135deg, #f7fbff 0%, #edf6ff 100%); box-shadow: var(--shadow); }
.feedback-copy h2 { margin: 7px 0 12px; font-size: clamp(30px, 4vw, 44px); line-height: 1.18; }
.feedback-copy > p:not(.section-kicker) { max-width: 660px; margin: 0; color: var(--muted); }
.feedback-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.feedback-email { display: inline-block; margin-top: 14px; color: var(--blue); font-size: 13px; overflow-wrap: anywhere; }
.feedback-guide { padding: 26px 28px; border: 1px solid var(--line); border-radius: var(--radius-md); background: rgba(255,255,255,.88); }
.feedback-guide > strong { display: block; margin-bottom: 12px; }
.feedback-guide ol { margin: 0; padding-left: 22px; color: var(--muted); font-size: 14px; }
.feedback-guide li + li { margin-top: 6px; }
.feedback-guide p { display: flex; gap: 9px; margin: 18px 0 0; padding-top: 16px; color: #765b36; border-top: 1px solid #efddc4; font-size: 12px; }
.feedback-guide p span { width: 20px; height: 20px; display: grid; place-items: center; flex: 0 0 auto; color: #fff; border-radius: 6px; background: var(--amber); font-weight: 900; }

.download-section { padding: 80px 0 110px; background: var(--soft); }
.download-card { position: relative; overflow: hidden; display: grid; grid-template-columns: 1fr auto; gap: 22px 40px; align-items: center; padding: 44px; color: #fff; border-radius: var(--radius-lg); background: #102f50; }
.download-card::after { content: ""; position: absolute; width: 270px; height: 270px; right: -100px; top: -150px; border: 56px solid rgba(255,255,255,.06); border-radius: 50%; }
.download-card h2 { margin: 7px 0 4px; font-size: clamp(31px, 4vw, 44px); line-height: 1.1; }
.download-card p:not(.section-kicker) { margin: 0; color: #b9cce0; }
.download-card .section-kicker { color: #7fc2ff; }
.download-actions { position: relative; z-index: 1; display: flex; gap: 10px; }
.checksum-button { min-height: 54px; padding: 0 18px; color: #fff; border: 1px solid rgba(255,255,255,.28); border-radius: 12px; background: transparent; cursor: pointer; }
.checksum-block { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(220px, .6fr) 1fr; gap: 24px; align-items: end; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.12); }
.checksum-block strong, .checksum-block span { display: block; }
.checksum-block strong { font-size: 13px; }
.checksum-block span { margin-top: 4px; color: #9fb4c9; font-size: 11px; line-height: 1.55; }
.checksum { overflow-wrap: anywhere; color: #9fb4c9; font-size: 11px; }

footer { padding: 32px 0; border-top: 1px solid var(--line); background: var(--surface); }
.footer-wrap { display: flex; align-items: center; gap: 24px; }
.footer-wrap p { margin: 0 auto 0 0; color: var(--muted); font-size: 12px; }
.footer-wrap > a { color: var(--blue); font-size: 12px; text-decoration: none; }

.lightbox { width: min(94vw, 980px); height: min(92vh, 920px); padding: 48px 70px 34px; border: 0; border-radius: 24px; background: #0c1420; color: #fff; }
.lightbox::backdrop { background: rgba(8, 15, 26, .82); backdrop-filter: blur(8px); }
.lightbox figure { height: 100%; margin: 0; display: grid; grid-template-rows: minmax(0, 1fr) auto; gap: 12px; }
.lightbox figure img { width: 100%; height: 100%; object-fit: contain; }
.lightbox figcaption { text-align: center; color: #c4d0dd; font-size: 13px; }
.lightbox-close, .lightbox-nav { position: absolute; display: grid; place-items: center; padding: 0; color: #fff; border: 1px solid rgba(255,255,255,.18); border-radius: 50%; background: rgba(255,255,255,.08); cursor: pointer; }
.lightbox-close { width: 38px; height: 38px; right: 18px; top: 18px; font-size: 25px; }
.lightbox-nav { width: 44px; height: 44px; top: 50%; transform: translateY(-50%); font-size: 30px; }
.lightbox-prev { left: 14px; }
.lightbox-next { right: 14px; }

:focus-visible { outline: 3px solid rgba(25,118,210,.35); outline-offset: 3px; }
@media (max-width: 980px) {
  .hero { padding-top: 70px; }
  .hero-grid { grid-template-columns: 1fr; gap: 45px; text-align: center; }
  .hero-copy { display: flex; flex-direction: column; align-items: center; }
  .product-stage { min-height: 560px; }
  .status-note--top { left: calc(50% - 260px); }
  .status-note--bottom { right: calc(50% - 270px); }
  .faq-layout { grid-template-columns: 1fr; gap: 22px; }
  .faq-intro { position: static; }
  .feedback-card { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  .shell { width: min(100% - 28px, var(--shell)); }
  .site-header .nav-links { display: none; }
  .nav-wrap { min-height: 64px; gap: 12px; }
  .nav-wrap > .button { margin-left: auto; }
  .hero { padding: 55px 0 70px; }
  .hero h1 { max-width: 100%; font-size: clamp(40px, 11.4vw, 48px); line-height: 1.12; letter-spacing: -.045em; }
  .hero-lead { font-size: 17px; }
  .hero-actions { width: 100%; }
  .hero-actions .button { width: 100%; }
  .download-fallback { align-items: flex-start; flex-direction: column; }
  .product-stage { min-height: 540px; }
  .phone-shot { width: 258px; }
  .status-note { min-width: 176px; padding: 11px 13px; }
  .status-note--top { top: 62px; left: 0; }
  .status-note--bottom { right: 0; bottom: 46px; }
  .trust-grid { grid-template-columns: 1fr; padding: 9px 0; }
  .trust-grid > div { padding: 17px 14px; }
  .trust-grid > div + div { border-left: 0; border-top: 1px solid var(--line); }
  .section { padding: 74px 0; }
  .section-heading { margin-bottom: 34px; }
  .section-heading h2 { font-size: 34px; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-card--wide { grid-column: auto; }
  .permission-list summary { grid-template-columns: 46px 1fr; padding: 18px; }
  .permission-list summary b { display: none; }
  .permission-body { padding: 0 18px 20px 80px; font-size: 13px; }
  .install-prelude { grid-template-columns: 1fr; }
  .guide-grid { display: flex; overflow-x: auto; gap: 14px; padding: 0 4px 14px; scroll-snap-type: x mandatory; scrollbar-width: thin; }
  .guide-card, .guide-card--last { min-width: min(86vw, 390px); min-height: 640px; grid-template-columns: 1fr; grid-template-rows: auto minmax(0, 1fr); scroll-snap-align: center; }
  .image-button { border-left: 0; border-top: 1px solid var(--line); }
  .guide-copy { padding: 22px; }
  .risk-callout { padding: 20px; }
  .feedback-card { gap: 28px; padding: 28px 22px; }
  .feedback-actions { flex-direction: column; }
  .feedback-actions .button { width: 100%; }
  .feedback-guide { padding: 22px 20px; }
  .download-card { grid-template-columns: 1fr; padding: 30px 24px; }
  .download-actions { flex-direction: column; }
  .checksum-block { grid-template-columns: 1fr; gap: 14px; }
  .footer-wrap { align-items: flex-start; flex-direction: column; gap: 12px; }
  .footer-wrap p { margin: 0; }
  .lightbox { padding: 56px 15px 25px; }
  .lightbox-nav { top: auto; bottom: 13px; transform: none; }
  .lightbox figcaption { padding: 0 50px; }
}

@media (max-width: 390px) {
  .brand > span:last-child { font-size: 14px; }
  .button--small { padding: 0 13px; }
  .status-note { display: none; }
  .product-stage { min-height: 500px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}