:root {
  --ink: #101713;
  --ink-soft: #44524a;
  --muted: #56655c;
  --line: #dce4df;
  --paper: #fff;
  --paper-soft: #f3f6f4;
  --dark: #07110c;
  --dark-soft: #0d1913;
  --brand: #087d4d;
  --brand-bright: #1ab56f;
  --brand-soft: #e5f5ec;
  --radius: 8px;
  --shell: min(1180px, calc(100% - 48px));
  --font: "SF Pro Display", "SF Pro Text", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 82px;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
}

body.nav-open { overflow: hidden; }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
button { color: inherit; font: inherit; }
h1, h2, h3, p, figure { margin-top: 0; }
h1, h2, h3 { letter-spacing: 0; }

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 100;
  padding: 8px 12px;
  transform: translateY(-150%);
  border-radius: 4px;
  background: #fff;
  color: #07110c;
}
.skip-link:focus { transform: translateY(0); }

.section-shell, .nav-shell, .hero-shell { width: var(--shell); margin-inline: auto; }
.section { padding: 112px 0; }

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 30;
  color: #fff;
  transition: background-color .2s ease, box-shadow .2s ease, color .2s ease;
}

.site-header.is-scrolled, .site-header.menu-open {
  background: rgba(255,255,255,.96);
  box-shadow: 0 1px 0 rgba(16, 23, 19, .08);
  color: var(--ink);
  backdrop-filter: blur(18px);
}

.nav-shell { display: flex; min-height: 76px; align-items: center; justify-content: space-between; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 21px; font-weight: 760; }
.brand img { width: 38px; height: 38px; border-radius: 8px; }
.brand small { margin-left: 2px; color: currentColor; font-size: 11px; font-weight: 500; opacity: .66; }
.site-nav { display: flex; align-items: center; gap: 32px; font-size: 14px; font-weight: 600; }
.site-nav a { opacity: .82; transition: opacity .2s ease; }
.site-nav a:hover { opacity: 1; }
.site-nav .nav-download { padding: 9px 16px; border: 1px solid rgba(255,255,255,.5); border-radius: 6px; opacity: 1; }
.site-header.is-scrolled .nav-download, .site-header.menu-open .nav-download { border-color: var(--line); background: var(--brand); color: #fff; }
.menu-toggle { display: none; width: 40px; height: 40px; border: 0; background: transparent; }
.menu-toggle span { display: block; width: 20px; height: 2px; margin: 5px auto; background: currentColor; }

.hero { position: relative; min-height: 760px; overflow: hidden; background: #0b1710; color: #fff; }
.hero-media { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: 54% center; }
.hero-scrim { position: absolute; inset: 0; background: linear-gradient(90deg, rgba(4,13,8,.9) 0%, rgba(4,13,8,.73) 37%, rgba(4,13,8,.12) 72%, rgba(4,13,8,.22) 100%); }
.hero-shell { position: relative; z-index: 1; display: flex; min-height: 760px; align-items: center; padding: 108px 0 68px; }
.hero-copy { width: min(790px, 68%); }
.mobile-break { display: none; }
.eyebrow, .section-index { margin-bottom: 18px; color: var(--brand); font-size: 12px; font-weight: 750; text-transform: uppercase; }
.hero .eyebrow, .modes-section .section-index, .download-section .section-index { color: var(--brand-bright); }
.hero h1 { margin-bottom: 26px; font-size: clamp(48px, 5.2vw, 68px); line-height: 1.12; font-weight: 500; }
.hero h1 strong { color: #7be7ad; font-weight: 760; }
.hero-lead { max-width: 610px; margin-bottom: 34px; color: rgba(255,255,255,.78); font-size: 18px; line-height: 1.8; }
.hero-actions { display: flex; align-items: center; gap: 28px; }
.button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; padding: 0 24px; border: 0; border-radius: 6px; font-size: 15px; font-weight: 750; }
.button-primary { background: var(--brand-bright); color: #04120a; }
.text-link { font-size: 14px; font-weight: 700; }
.text-link span { margin-left: 8px; }
.hero-facts { display: flex; gap: 28px; margin-top: 54px; color: rgba(255,255,255,.68); font-size: 13px; }
.hero-facts span { display: flex; align-items: center; gap: 9px; }
.hero-facts b { color: #7be7ad; font-size: 11px; }

.problem-band { border-bottom: 1px solid var(--line); background: #fff; }
.problem-band .section-shell { display: grid; min-height: 154px; grid-template-columns: 1.15fr 2.3fr; align-items: stretch; }
.problem-intro { display: flex; flex-direction: column; justify-content: center; border-right: 1px solid var(--line); }
.problem-intro span { color: var(--muted); font-size: 13px; }
.problem-intro strong { font-size: 21px; }
.problem-points { display: grid; grid-template-columns: repeat(3, 1fr); }
.problem-points article { display: flex; flex-direction: column; justify-content: center; padding-left: 34px; }
.problem-points span { margin-bottom: 4px; color: var(--muted); font-size: 13px; }
.problem-points strong { font-size: 16px; }

.section-heading { margin-bottom: 58px; }
.split-heading { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(280px, .8fr); gap: 70px; align-items: end; }
.section-heading h2, .download-copy h2, .reliability-copy h2 { margin-bottom: 0; font-size: clamp(36px, 4vw, 50px); line-height: 1.18; font-weight: 710; }
.split-heading > p { max-width: 440px; margin-bottom: 4px; color: var(--muted); font-size: 16px; line-height: 1.85; }

.product-section { background: var(--paper-soft); }
.product-stage { display: grid; grid-template-columns: minmax(300px, .82fr) minmax(0, 1.18fr); gap: 90px; align-items: center; }
.phone-frame { position: relative; width: min(380px, 100%); margin-inline: auto; padding: 10px; border: 1px solid #26332c; border-radius: 34px; background: #131b17; box-shadow: 0 30px 70px rgba(9, 27, 17, .17); }
.phone-frame::before { position: absolute; top: 17px; left: 50%; z-index: 2; width: 74px; height: 20px; transform: translateX(-50%); border-radius: 15px; background: #101713; content: ""; }
.phone-screen { min-height: 680px; overflow: hidden; padding: 42px 18px 20px; border-radius: 26px; background: #f4f7f5; color: #111b15; }
.app-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; padding: 0 4px; }
.app-top > div { display: flex; align-items: center; gap: 9px; }
.app-top img { width: 34px; height: 34px; border-radius: 8px; }
.app-top span { display: flex; flex-direction: column; line-height: 1.25; }
.app-top strong { font-size: 16px; }
.app-top small { color: #758279; font-size: 9px; }
.app-top > b { color: #849087; letter-spacing: 2px; }
.phone-screen section { margin-bottom: 12px; padding: 16px; border-radius: 8px; background: #fff; }
.app-status { overflow: hidden; border-top: 3px solid var(--brand); }
.app-status > div:first-child { display: flex; align-items: center; justify-content: space-between; }
.app-status > div:first-child span, .app-status > small { color: #7b887f; font-size: 10px; }
.app-status > div:first-child strong { color: var(--brand); font-size: 26px; }
.app-status > small { display: block; margin: 3px 0 16px; }
.app-links { display: grid; margin: 0 -16px -16px; grid-template-columns: repeat(3, 1fr); border-top: 1px solid #edf1ee; }
.app-links span { display: flex; min-width: 0; flex-direction: column; align-items: center; padding: 10px 2px; color: #7c8981; font-size: 9px; }
.app-links span + span { border-left: 1px solid #edf1ee; }
.app-links b { color: #26342c; font-size: 10px; }
.phone-screen section header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.phone-screen section header strong { font-size: 13px; }
.phone-screen section header span { color: var(--brand); font-size: 9px; }
.app-ready > div, .app-config > div { display: flex; align-items: center; justify-content: space-between; min-height: 44px; border-top: 1px solid #eef2ef; color: #56635b; font-size: 11px; }
.app-ready b, .app-config b { color: #1d2a22; font-size: 10px; }
.phone-screen button { width: 100%; height: 48px; margin-top: 4px; border: 0; border-radius: 7px; background: var(--brand); color: #fff; font-size: 13px; font-weight: 750; }
.product-flow { border-top: 1px solid #cad5ce; }
.product-flow > article { display: grid; grid-template-columns: 54px 1fr; gap: 24px; align-items: center; min-height: 106px; border-bottom: 1px solid #cad5ce; }
.product-flow > article > span { color: var(--brand); font-size: 13px; font-weight: 800; }
.product-flow article div { display: flex; flex-direction: column; gap: 4px; }
.product-flow small { color: var(--muted); font-size: 12px; }
.product-flow strong { font-size: 18px; font-weight: 680; }
.product-feature-line { display: flex; flex-wrap: wrap; gap: 8px; padding-top: 24px; }
.product-feature-line span { padding: 7px 10px; border: 1px solid #ced9d2; border-radius: 4px; color: #4d5b53; font-size: 11px; }

.modes-section { background: var(--dark); color: #fff; }
.section-heading-light h2 { color: #fff; }
.section-heading-light > p { color: rgba(255,255,255,.62); }
.mode-rows { border-top: 1px solid rgba(255,255,255,.15); }
.mode-rows article { display: grid; min-height: 220px; grid-template-columns: 180px minmax(0, 1fr) 270px; gap: 34px; align-items: center; border-bottom: 1px solid rgba(255,255,255,.15); }
.mode-mark { display: flex; align-items: center; gap: 24px; color: #67d99a; font-size: 12px; }
.audio-wave { display: flex; height: 42px; align-items: center; gap: 4px; }
.audio-wave i { width: 3px; height: 18px; border-radius: 3px; background: #67d99a; }
.audio-wave i:nth-child(2), .audio-wave i:nth-child(4) { height: 34px; }
.audio-wave i:nth-child(3) { height: 25px; }
.standby-signal { position: relative; width: 48px; height: 48px; }
.standby-signal i { position: absolute; inset: 50%; border: 1px solid #67d99a; border-radius: 50%; transform: translate(-50%, -50%); }
.standby-signal i:nth-child(1) { width: 10px; height: 10px; background: #67d99a; }
.standby-signal i:nth-child(2) { width: 28px; height: 28px; opacity: .65; }
.standby-signal i:nth-child(3) { width: 48px; height: 48px; opacity: .25; }
.mode-rows small { color: #67d99a; font-size: 11px; }
.mode-rows h3 { margin: 8px 0 8px; font-size: 25px; }
.mode-rows p { margin-bottom: 0; color: rgba(255,255,255,.62); font-size: 14px; }
.mode-rows article > strong { color: rgba(255,255,255,.55); font-size: 13px; font-weight: 500; text-align: right; }
.local-audio-band { display: grid; margin-top: 32px; padding: 24px 28px; grid-template-columns: 130px minmax(0, 1fr) auto; gap: 28px; align-items: center; background: #13251b; border-left: 3px solid var(--brand-bright); }
.local-audio-band span { color: #70dca0; font-size: 12px; font-weight: 750; }
.local-audio-band strong { font-size: 16px; }
.local-audio-band p { margin-bottom: 0; color: rgba(255,255,255,.55); font-size: 12px; }

.scenes-section { background: #fff; }
.scene-gallery { display: grid; grid-template-columns: 1.35fr 1fr 1fr; gap: 12px; }
.scene-card { position: relative; min-height: 440px; overflow: hidden; border-radius: var(--radius); background: #18231d; color: #fff; }
.scene-card::after { position: absolute; inset: 0; background: linear-gradient(180deg, transparent 42%, rgba(3,9,6,.88) 100%); content: ""; }
.scene-card img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.scene-card:hover img { transform: scale(1.025); }
.scene-card > div { position: absolute; right: 24px; bottom: 22px; left: 24px; z-index: 1; }
.scene-card span { color: #8ee5b5; font-size: 11px; font-weight: 750; }
.scene-card h3 { margin: 7px 0 4px; font-size: 20px; line-height: 1.35; }
.scene-card p { margin-bottom: 0; color: rgba(255,255,255,.68); font-size: 12px; }
.scene-tags { display: grid; margin-top: 12px; grid-template-columns: repeat(6, 1fr); border: 1px solid var(--line); border-radius: 6px; }
.scene-tags span { padding: 14px 4px; color: #526057; font-size: 12px; text-align: center; }
.scene-tags span + span { border-left: 1px solid var(--line); }

.reliability-section { background: var(--brand-soft); }
.reliability-shell { display: grid; grid-template-columns: .85fr 1.15fr; gap: 90px; }
.reliability-copy p:last-child { max-width: 410px; margin-top: 24px; margin-bottom: 0; color: #506258; }
.reliability-list { border-top: 1px solid rgba(8,125,77,.24); }
.reliability-list article { display: grid; min-height: 94px; grid-template-columns: 120px 1fr; gap: 24px; align-items: center; border-bottom: 1px solid rgba(8,125,77,.24); }
.reliability-list span { color: var(--brand); font-size: 12px; font-weight: 750; }
.reliability-list strong { font-size: 16px; font-weight: 620; }

.faq-section { background: #fff; }
.faq-shell { display: grid; grid-template-columns: .8fr 1.2fr; gap: 90px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { position: relative; padding: 24px 42px 24px 0; cursor: pointer; list-style: none; font-size: 17px; font-weight: 680; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { position: absolute; top: 24px; right: 4px; color: var(--brand); content: "+"; font-size: 22px; line-height: 1; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { max-width: 650px; margin: -5px 44px 22px 0; color: var(--muted); font-size: 14px; }

.download-section { padding: 100px 0; background: var(--dark); color: #fff; }
.download-shell { display: grid; grid-template-columns: 1fr 230px; gap: 80px; align-items: center; }
.download-copy > p:not(.section-index):not(.download-note) { max-width: 620px; margin: 24px 0 30px; color: rgba(255,255,255,.63); }
.download-actions { display: flex; align-items: center; gap: 20px; }
.download-actions span, .download-note { color: rgba(255,255,255,.5); font-size: 12px; }
.download-note { margin: 12px 0 0; }
.download-qr { padding: 14px; border-radius: 8px; background: #fff; color: #4f5d55; text-align: center; }
.download-qr img { width: 100%; height: auto; aspect-ratio: 1; }
.download-qr figcaption { margin-top: 8px; font-size: 11px; }

.site-footer { background: #050c08; color: rgba(255,255,255,.55); }
.footer-inner { display: grid; min-height: 104px; grid-template-columns: auto 1fr auto; gap: 34px; align-items: center; }
.footer-brand { color: #fff; }
.footer-inner p { margin-bottom: 0; font-size: 12px; }

@media (max-width: 980px) {
  .site-nav { gap: 20px; }
  .hero-copy { width: 70%; }
  .problem-band .section-shell { grid-template-columns: 1fr; }
  .problem-intro { min-height: 100px; border-right: 0; border-bottom: 1px solid var(--line); }
  .problem-points article { min-height: 100px; padding-left: 0; }
  .product-stage { grid-template-columns: 340px 1fr; gap: 46px; }
  .mode-rows article { grid-template-columns: 130px 1fr; }
  .mode-rows article > strong { grid-column: 2; margin-top: -24px; text-align: left; }
  .scene-gallery { grid-template-columns: 1fr 1fr; }
  .scene-store { grid-row: span 2; }
  .scene-card { min-height: 300px; }
  .scene-store { min-height: 612px; }
}

@media (max-width: 760px) {
  :root { --shell: calc(100% - 32px); }
  html { scroll-padding-top: 66px; }
  .section { padding: 74px 0; }
  .nav-shell { min-height: 64px; }
  .brand { font-size: 19px; }
  .brand img { width: 34px; height: 34px; }
  .brand small { display: none; }
  .menu-toggle { display: block; }
  .site-nav { position: fixed; top: 64px; right: 0; left: 0; display: none; height: calc(100vh - 64px); padding: 32px 16px; flex-direction: column; align-items: stretch; gap: 0; background: #fff; color: var(--ink); }
  .site-header.menu-open .site-nav { display: flex; }
  .site-nav a { padding: 16px 0; border-bottom: 1px solid var(--line); font-size: 17px; }
  .site-nav .nav-download { margin-top: 24px; padding: 13px 16px; border: 0; background: var(--brand); color: #fff; text-align: center; }

  .hero { min-height: 700px; }
  .hero-media { object-position: 64% center; }
  .hero-scrim { background: linear-gradient(180deg, rgba(4,13,8,.82) 0%, rgba(4,13,8,.68) 52%, rgba(4,13,8,.88) 100%); }
  .hero-shell { min-height: 700px; align-items: flex-end; padding: 104px 0 52px; }
  .hero-copy { width: 100%; }
  .mobile-break { display: inline; }
  .eyebrow { margin-bottom: 12px; font-size: 11px; }
  .hero h1 { margin-bottom: 20px; font-size: 39px; line-height: 1.16; }
  .hero-lead { max-width: 520px; margin-bottom: 26px; font-size: 15px; line-height: 1.72; }
  .hero-actions { gap: 22px; }
  .hero-actions .button { min-height: 44px; padding: 0 18px; }
  .hero-facts { margin-top: 34px; flex-wrap: wrap; gap: 7px 18px; font-size: 11px; }

  .problem-band .section-shell { display: block; }
  .problem-intro { min-height: 100px; }
  .problem-intro strong { font-size: 19px; }
  .problem-points { display: block; padding: 8px 0; }
  .problem-points article { min-height: 66px; padding: 10px 0; border-bottom: 1px solid var(--line); }
  .problem-points article:last-child { border-bottom: 0; }
  .problem-points span { margin-bottom: 1px; font-size: 11px; }
  .problem-points strong { font-size: 14px; }

  .section-heading { margin-bottom: 38px; }
  .split-heading { display: block; }
  .section-heading h2, .download-copy h2, .reliability-copy h2 { font-size: 31px; }
  .split-heading > p { margin-top: 18px; font-size: 14px; }
  .section-index { margin-bottom: 12px; font-size: 11px; }

  .product-stage { display: block; }
  .phone-frame { width: min(330px, 94%); }
  .phone-screen { min-height: 590px; padding: 38px 14px 16px; }
  .phone-screen section { padding: 13px; }
  .app-links { margin-right: -13px; margin-bottom: -13px; margin-left: -13px; }
  .product-flow { margin-top: 52px; }
  .product-flow > article { min-height: 92px; grid-template-columns: 36px 1fr; gap: 10px; }
  .product-flow strong { font-size: 15px; }

  .mode-rows article { display: block; min-height: 0; padding: 30px 0; }
  .mode-mark { margin-bottom: 18px; }
  .mode-rows h3 { font-size: 22px; }
  .mode-rows article > strong { display: block; margin-top: 18px; font-size: 11px; text-align: left; }
  .local-audio-band { display: block; margin-top: 22px; padding: 20px; }
  .local-audio-band strong { display: block; margin: 8px 0; font-size: 14px; }

  .scene-gallery { display: block; }
  .scene-card, .scene-store { min-height: 330px; margin-bottom: 10px; }
  .scene-card > div { right: 18px; bottom: 18px; left: 18px; }
  .scene-card h3 { font-size: 19px; }
  .scene-tags { grid-template-columns: repeat(3, 1fr); }
  .scene-tags span:nth-child(3n + 1) { border-left: 0; }
  .scene-tags span:nth-child(n + 4) { border-top: 1px solid var(--line); }

  .reliability-shell, .faq-shell { display: block; }
  .reliability-copy p:last-child { margin-top: 18px; font-size: 14px; }
  .reliability-list, .faq-list { margin-top: 40px; }
  .reliability-list article { min-height: 94px; grid-template-columns: 88px 1fr; gap: 12px; }
  .reliability-list strong { font-size: 14px; }
  .faq-list summary { padding: 20px 34px 20px 0; font-size: 15px; }
  .faq-list summary::after { top: 20px; }
  .faq-list details p { margin-right: 20px; font-size: 13px; }

  .download-section { padding: 74px 0; }
  .download-shell { display: flex; flex-direction: column; gap: 38px; align-items: stretch; }
  .download-actions { flex-direction: column; align-items: flex-start; gap: 12px; }
  .download-actions .button { width: 100%; }
  .download-qr { width: min(220px, 75%); margin-inline: auto; }
  .footer-inner { display: flex; min-height: 130px; flex-wrap: wrap; gap: 12px 24px; padding: 24px 0; }
  .footer-inner > p:first-of-type { width: 100%; order: 3; }
}

@media (max-width: 380px) {
  .hero h1 { font-size: 36px; }
  .hero-facts { gap: 6px 11px; }
  .phone-frame { width: 100%; }
  .scene-tags span { font-size: 11px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}

:focus-visible { outline: 3px solid #67d99a; outline-offset: 3px; }