:root {
  --ink: #162327;
  --ink-2: #40545a;
  --muted: #637579;
  --paper: #f5f2e9;
  --paper-2: #fbfaf6;
  --mint: #37d2aa;
  --mint-dark: #0e6b58;
  --gold: #e1b758;
  --line: #d8ded8;
  --navy: #0c1c22;
  --navy-2: #132b32;
  --white: #fff;
  --shadow: 0 26px 70px rgba(17, 36, 40, .12);
  --radius-xl: 30px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --container: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper-2);
  font-family: Arial, "Microsoft YaHei", "PingFang SC", "Helvetica Neue", sans-serif;
  font-size: 16px;
  line-height: 1.82;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
img { display: block; max-width: 100%; height: auto; }
button, a { -webkit-tap-highlight-color: transparent; }
.container { width: min(var(--container), calc(100% - 40px)); margin-inline: auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(251,250,246,.94);
  border-bottom: 1px solid rgba(22,35,39,.09);
  backdrop-filter: blur(16px);
}
.header-inner {
  width: min(1220px, calc(100% - 40px));
  min-height: 74px;
  margin: auto;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 26px;
}
.brand { display: inline-flex; align-items: center; text-decoration: none; flex-shrink: 0; }
.brand-shell { display: inline-flex; align-items: center; min-width: max-content; }
.brand img { width: auto; height: 38px; max-width: 180px; max-height: 42px; object-fit: contain; flex-shrink: 0; }
.primary-nav { display: flex; justify-content: center; gap: 28px; }
.primary-nav a { color: #44585e; text-decoration: none; font-size: 14px; font-weight: 700; }
.primary-nav a:hover { color: var(--mint-dark); }
.top-download {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 44px; padding: 0 20px; border-radius: 12px;
  background: var(--navy); color: #fff; text-decoration: none; font-weight: 800; font-size: 14px;
}

.hero { background: var(--paper); padding: 42px 0 0; overflow: hidden; }
.hero-inner { width: min(1220px, calc(100% - 40px)); margin: auto; }
.hero-topline {
  display: flex; align-items: center; justify-content: space-between; gap: 20px;
  padding-bottom: 18px; border-bottom: 1px solid rgba(22,35,39,.16);
  color: #5b6b6f; font-size: 13px; font-weight: 700; letter-spacing: .04em;
}
.hero-title-row {
  display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(360px, .88fr);
  gap: 72px; align-items: end; padding: 58px 0 42px;
}
.hero-kicker, .eyebrow {
  margin: 0 0 12px; color: var(--mint-dark); font-size: 12px; font-weight: 900; letter-spacing: .15em;
}
h1, h2, h3, p { margin-top: 0; }
h1 {
  margin-bottom: 0; font-size: clamp(46px, 6vw, 80px); line-height: 1.02; letter-spacing: -.045em;
  font-weight: 900;
}
.hero-summary { padding-bottom: 6px; }
.hero-summary p { margin-bottom: 24px; color: #4a5e63; font-size: 18px; line-height: 1.9; }
.hero-actions { display: flex; align-items: center; gap: 22px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 50px; padding: 13px 24px; border-radius: 14px; text-decoration: none;
  font-weight: 900; line-height: 1.2; transition: transform .2s ease, box-shadow .2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--mint); color: #06251c; box-shadow: 0 12px 30px rgba(55,210,170,.2); }
.btn-dark { background: var(--navy); color: #fff; }
.text-action { color: var(--ink); text-decoration: none; font-weight: 800; }
.text-action span { display: inline-block; margin-left: 8px; color: var(--mint-dark); }

.hero-media {
  position: relative; margin: 0; min-height: 430px; border-radius: 34px 34px 0 0; overflow: hidden;
  background: linear-gradient(135deg, #16333a 0%, #0b1c22 62%, #07151a 100%);
  box-shadow: var(--shadow);
}
.hero-media::after {
  content: ""; position: absolute; inset: auto -8% -38% auto; width: 420px; height: 420px;
  border-radius: 50%; border: 1px solid rgba(255,255,255,.14); box-shadow: 0 0 0 40px rgba(255,255,255,.035), 0 0 0 88px rgba(255,255,255,.02);
}
.hero-media img { width: 100%; height: 430px; object-fit: contain; padding: 26px 160px 26px 34px; position: relative; z-index: 2; }
.hero-media figcaption {
  position: absolute; right: 34px; top: 34px; z-index: 3;
  width: 260px; padding: 22px; border-radius: 20px; background: rgba(255,255,255,.1); color: #fff;
  border: 1px solid rgba(255,255,255,.16); backdrop-filter: blur(10px);
}
.hero-media figcaption strong { display: block; margin-bottom: 4px; font-size: 18px; }
.hero-media figcaption span { color: #cbd9dc; font-size: 14px; }

.device-picker { background: #fff; padding: 94px 0; }
.device-picker-inner { display: grid; grid-template-columns: 360px 1fr; gap: 70px; align-items: start; }
.picker-heading { position: sticky; top: 110px; }
.picker-heading h2, .flow-head h2, .feature-title h2, .trouble-title h2, .related-heading h2, .faq-intro h2, .proof-copy h2, .final-inner h2 {
  margin-bottom: 18px; font-size: clamp(30px, 3.4vw, 46px); line-height: 1.16; letter-spacing: -.035em;
}
.picker-heading p, .flow-head p, .feature-title p, .trouble-title p, .faq-intro p, .proof-copy > p, .final-inner p { color: var(--ink-2); }
.device-rows { border-top: 1px solid var(--line); }
.device-row {
  display: grid; grid-template-columns: 72px 1fr auto; gap: 24px; align-items: center;
  padding: 30px 0; border-bottom: 1px solid var(--line);
}
.device-no {
  width: 54px; height: 54px; border-radius: 16px; display: grid; place-items: center; font-weight: 900;
  background: #edf5f2; color: var(--mint-dark);
}
.device-copy h3 { margin-bottom: 6px; font-size: 22px; }
.device-copy p { margin-bottom: 8px; color: #5b6b70; }
.inline-link { color: var(--mint-dark); text-decoration: none; font-weight: 800; font-size: 14px; }
.device-download {
  min-width: 168px; min-height: 46px; padding: 10px 18px; border: 1px solid #bac8c3; border-radius: 12px;
  text-decoration: none; font-weight: 900; text-align: center;
}
.device-download:hover { background: var(--navy); border-color: var(--navy); color: #fff; }
.device-download span { margin-left: 8px; }

.client-proof { padding: 94px 0; background: #e8f1ed; }
.proof-grid { display: grid; grid-template-columns: .92fr 1.08fr; gap: 72px; align-items: center; }
.proof-list { margin: 30px 0; }
.proof-list > div { display: grid; grid-template-columns: 120px 1fr; gap: 24px; padding: 16px 0; border-top: 1px solid rgba(22,35,39,.14); }
.proof-list > div:last-child { border-bottom: 1px solid rgba(22,35,39,.14); }
.proof-list dt { font-weight: 900; }
.proof-list dd { margin: 0; color: #52656a; }
.phone-shot { margin: 0; min-height: 520px; position: relative; display: grid; place-items: center; border-radius: var(--radius-xl); background: #fff; box-shadow: var(--shadow); overflow: hidden; }
.phone-shot::before { content: ""; position: absolute; inset: 28px; border: 1px solid #dfe7e3; border-radius: 24px; }
.phone-shot img { position: relative; z-index: 2; max-height: 450px; object-fit: contain; padding: 34px; }
.shot-caption { position: absolute; top: 22px; left: 28px; z-index: 3; padding: 7px 11px; border-radius: 999px; background: var(--navy); color: #fff; font-size: 12px; font-weight: 800; }

.install-flow { padding: 96px 0; background: var(--navy); color: #fff; }
.flow-head { display: grid; grid-template-columns: 1fr 420px; gap: 60px; align-items: end; margin-bottom: 48px; }
.flow-head h2 { color: #fff; margin-bottom: 0; }
.flow-head p { color: #b8c8cc; margin-bottom: 4px; }
.flow-strip { margin: 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid rgba(255,255,255,.18); border-bottom: 1px solid rgba(255,255,255,.18); }
.flow-strip li { min-height: 190px; padding: 28px 24px; border-right: 1px solid rgba(255,255,255,.16); }
.flow-strip li:last-child { border-right: 0; }
.flow-strip li > span { display: block; color: var(--mint); font-size: 13px; font-weight: 900; letter-spacing: .12em; margin-bottom: 28px; }
.flow-strip h3 { margin-bottom: 8px; font-size: 21px; }
.flow-strip p { color: #b8c8cc; margin-bottom: 0; font-size: 15px; }

.feature-visual { padding: 100px 0; background: var(--paper); }
.feature-shell { display: grid; grid-template-columns: 380px 1fr; gap: 64px 70px; align-items: start; }
.feature-title { padding-top: 20px; }
.feature-image { margin: 0; min-height: 450px; display: grid; place-items: center; border-radius: 30px; background: #fff; box-shadow: var(--shadow); overflow: hidden; }
.feature-image img { width: 100%; max-height: 450px; object-fit: contain; padding: 26px; }
.feature-notes { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid #cdd5d1; border-bottom: 1px solid #cdd5d1; }
.feature-notes > div { padding: 26px 28px; border-right: 1px solid #cdd5d1; }
.feature-notes > div:last-child { border-right: 0; }
.feature-notes b { display: block; margin-bottom: 6px; font-size: 18px; }
.feature-notes span { color: #56676b; }

.troubleshoot { padding: 100px 0; background: #fff; }
.troubleshoot-grid { display: grid; grid-template-columns: 340px 1fr; gap: 70px; }
.trouble-list { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.trouble-list article { min-height: 190px; padding: 26px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.trouble-list article > span { color: var(--mint-dark); font-size: 12px; font-weight: 900; letter-spacing: .14em; }
.trouble-list h3 { margin: 24px 0 8px; font-size: 20px; }
.trouble-list p { margin-bottom: 0; color: #5a6b70; }
.btn-wide { grid-column: 2; width: 100%; margin-top: -26px; }

.related { padding: 84px 0; background: #eef3f0; }
.related-shell { display: grid; grid-template-columns: 320px 1fr; gap: 70px; }
.related-links { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.related-links a { padding: 20px 22px; background: #fff; border-radius: 16px; text-decoration: none; border: 1px solid #d9e2de; }
.related-links strong { display: block; margin-bottom: 4px; }
.related-links span { color: #607176; font-size: 14px; }
.related-links a:hover { border-color: var(--mint-dark); }

.faq { padding: 100px 0; background: #fff; }
.faq-grid { display: grid; grid-template-columns: 340px 1fr; gap: 72px; align-items: start; }
.faq-list { border-top: 1px solid var(--line); }
details { border-bottom: 1px solid var(--line); }
summary { cursor: pointer; list-style: none; padding: 24px 46px 24px 0; position: relative; font-size: 18px; font-weight: 900; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 4px; top: 19px; font-size: 28px; color: var(--mint-dark); }
details[open] summary::after { content: "–"; }
details p { padding: 0 52px 26px 0; margin: 0; color: #55676c; }

.final-cta { padding: 78px 0; background: linear-gradient(135deg, #14353c, #0b2026); color: #fff; }
.final-inner { display: grid; grid-template-columns: 1fr auto; gap: 48px; align-items: center; }
.final-inner h2 { margin-bottom: 12px; color: #fff; }
.final-inner p { margin-bottom: 0; color: #bed0d4; max-width: 760px; }
.eyebrow-light { color: #75e0c4; }
.btn-large { min-height: 58px; padding-inline: 30px; white-space: nowrap; }

.site-footer { padding: 56px 0 96px; background: #071419; color: #fff; }
.footer-grid { display: grid; grid-template-columns: 1.4fr .8fr .8fr; gap: 70px; }
.footer-brand p { max-width: 420px; margin: 20px 0 0; color: #9eb0b5; font-size: 14px; }
.footer-logo .brand-shell { padding: 7px 10px; border-radius: 10px; background: #fff; }
.footer-col { display: flex; flex-direction: column; align-items: flex-start; gap: 9px; }
.footer-col strong { margin-bottom: 7px; color: #fff; }
.footer-col a { color: #aebfc3; text-decoration: none; font-size: 14px; }
.footer-col a:hover { color: #fff; }

.mobile-download-bar { display: none; }

@media (max-width: 1024px) {
  .primary-nav { display: none; }
  .header-inner { grid-template-columns: 1fr auto; }
  .hero-title-row { grid-template-columns: 1fr; gap: 30px; padding-top: 46px; }
  .hero-summary { max-width: 720px; }
  .hero-media img { padding-right: 80px; }
  .hero-media figcaption { width: 230px; }
  .device-picker-inner, .proof-grid, .feature-shell, .troubleshoot-grid, .related-shell, .faq-grid { grid-template-columns: 1fr; gap: 44px; }
  .picker-heading { position: static; }
  .flow-head { grid-template-columns: 1fr; gap: 20px; }
  .feature-notes, .feature-image { grid-column: 1; }
  .btn-wide { grid-column: 1; margin-top: 0; }
}

@media (max-width: 768px) {
  body { font-size: 15.5px; padding-bottom: 68px; }
  .container, .header-inner, .hero-inner { width: min(100% - 28px, var(--container)); }
  .site-header { position: relative; }
  .header-inner { min-height: 66px; gap: 12px; }
  .brand img { height: 32px; max-width: 150px; }
  .top-download { min-height: 40px; padding: 0 14px; font-size: 13px; }
  .hero { padding-top: 26px; }
  .hero-topline { align-items: flex-start; flex-direction: column; gap: 4px; }
  .hero-title-row { padding: 36px 0 28px; }
  h1 { font-size: clamp(40px, 13vw, 58px); }
  .hero-summary p { font-size: 16px; }
  .hero-media { min-height: 360px; border-radius: 24px 24px 0 0; }
  .hero-media img { height: 360px; padding: 24px 18px 110px; }
  .hero-media figcaption { left: 18px; right: 18px; top: auto; bottom: 18px; width: auto; }
  .device-picker, .client-proof, .install-flow, .feature-visual, .troubleshoot, .faq { padding: 64px 0; }
  .device-row { grid-template-columns: 54px 1fr; gap: 14px 18px; }
  .device-download { grid-column: 1 / -1; width: 100%; }
  .proof-list > div { grid-template-columns: 1fr; gap: 3px; }
  .phone-shot { min-height: 390px; }
  .phone-shot img { max-height: 340px; padding: 30px 18px; }
  .flow-strip { grid-template-columns: 1fr; }
  .flow-strip li { min-height: 0; border-right: 0; border-bottom: 1px solid rgba(255,255,255,.16); }
  .flow-strip li:last-child { border-bottom: 0; }
  .feature-notes { grid-template-columns: 1fr; }
  .feature-notes > div { border-right: 0; border-bottom: 1px solid #cdd5d1; }
  .feature-notes > div:last-child { border-bottom: 0; }
  .trouble-list, .related-links { grid-template-columns: 1fr; }
  .final-inner { grid-template-columns: 1fr; }
  .btn-large { width: 100%; }
  .footer-grid { grid-template-columns: 1fr; gap: 34px; }
  .mobile-download-bar {
    display: block; position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
    padding: 9px 12px; background: rgba(7,20,25,.96); border-top: 1px solid rgba(255,255,255,.12);
  }
  .mobile-download-bar a {
    display: flex; min-height: 48px; align-items: center; justify-content: center;
    border-radius: 12px; background: var(--mint); color: #052219; text-decoration: none; font-weight: 900;
  }
}

@media (max-width: 520px) {
  .hero-actions { align-items: stretch; flex-direction: column; }
  .hero-actions .btn, .text-action { width: 100%; text-align: center; }
  .hero-media { min-height: 330px; }
  .hero-media img { height: 330px; }
  .device-row { grid-template-columns: 1fr; }
  .device-no { width: 48px; height: 48px; }
  .device-download { grid-column: 1; }
  .feature-image { min-height: 320px; }
  .related, .final-cta { padding: 60px 0; }
}