:root {
  color-scheme: dark;
  --bg: #05070a;
  --surface: #0c1016;
  --text: #f5f7fa;
  --muted: #9299a5;
  --line: rgba(255, 255, 255, .1);
  --blue: #75b9ff;
  --max: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", Arial, sans-serif; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
[data-en] { display: none; }
html[lang="en"] [data-zh] { display: none; }
html[lang="en"] [data-en] { display: inline; }

.nav { position: fixed; z-index: 20; top: 0; left: 0; width: 100vw; height: 76px; display: flex; align-items: center; justify-content: space-between; padding: 0 max(24px, calc((100vw - var(--max)) / 2)); background: linear-gradient(to bottom, rgba(5, 7, 10, .9), transparent); }
.brand, .footer-brand { display: flex; align-items: center; gap: 11px; font-size: 15px; font-weight: 650; letter-spacing: -.01em; }
.brand img, .footer-brand img { border-radius: 22%; box-shadow: 0 5px 16px rgba(0, 0, 0, .35); }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.language { width: 40px; height: 36px; border: 0; color: #c7cbd2; background: transparent; cursor: pointer; font-size: 12px; font-weight: 650; }
.nav-download { padding: 10px 18px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255, 255, 255, .08); backdrop-filter: blur(16px); font-size: 13px; font-weight: 600; transition: .25s ease; }
.nav-download:hover { background: #fff; color: #090a0d; }

.hero { min-height: 100svh; position: relative; display: grid; grid-template-columns: .9fr 1.1fr; align-items: center; gap: 42px; max-width: 1440px; margin: auto; padding: 110px max(40px, calc((100vw - var(--max)) / 2)) 80px; isolation: isolate; }
.aurora { position: absolute; z-index: -1; width: 850px; height: 720px; top: -270px; right: -170px; background: radial-gradient(ellipse, rgba(49, 124, 218, .2), transparent 65%); filter: blur(30px); }
.hero-copy { position: relative; z-index: 2; }
.eyebrow { margin: 0 0 20px; color: var(--blue); font-size: 12px; font-weight: 700; letter-spacing: .16em; text-transform: uppercase; }
h1 { margin: 0; font-size: clamp(58px, 5.3vw, 80px); line-height: .98; letter-spacing: -.065em; font-weight: 650; }
.hero-title-line { display: block; white-space: nowrap; }
.hero-description { margin: 30px 0 28px; color: #aeb4be; font-size: clamp(16px, 1.4vw, 20px); line-height: 1.75; }
.app-store-button { display: inline-flex; align-items: center; gap: 11px; min-width: 174px; padding: 10px 18px 10px 16px; border-radius: 13px; color: #090a0d; background: #f5f5f7; transition: transform .25s ease, box-shadow .25s ease; }
.app-store-button:hover { transform: translateY(-2px); box-shadow: 0 14px 38px rgba(117, 185, 255, .15); }
.app-store-button svg { width: 28px; fill: currentColor; }
.app-store-button span { display: flex; flex-direction: column; align-items: flex-start; }
.app-store-button small { font-size: 10px; line-height: 1; }
.app-store-button strong { font-size: 20px; line-height: 1.1; font-weight: 600; }
.requirements { color: #6f7680; font-size: 11px; margin: 13px 0 0; }

.device-wrap { position: relative; z-index: 1; transform: perspective(1200px) rotateY(-7deg) rotateX(2deg); }
.device-glow { position: absolute; inset: 14% 5% 2%; background: #207dce; filter: blur(100px); opacity: .22; }
.device { position: relative; width: min(760px, 54vw); aspect-ratio: 2.164 / 1; margin: auto; padding: 10px; border: 1px solid rgba(255, 255, 255, .17); border-radius: 42px; background: linear-gradient(145deg, #34373b, #08090b 40%, #202225); box-shadow: 0 45px 100px rgba(0, 0, 0, .65), inset 0 0 0 2px #050506; }
.device-screen { position: relative; width: 100%; height: 100%; border-radius: 32px; overflow: hidden; background: #000; }
.device-screen img { display: block; width: 100%; height: 100%; object-fit: cover; }
.sensor { position: absolute; top: 50%; left: 4px; width: 4px; height: 54px; transform: translateY(-50%); border-radius: 9px; background: #030405; }
.scroll-cue { position: absolute; bottom: 25px; left: 50%; width: 28px; height: 44px; display: grid; place-items: center; transform: translateX(-50%); border: 1px solid rgba(255, 255, 255, .18); border-radius: 18px; }
.scroll-cue span { width: 3px; height: 7px; border-radius: 3px; background: #fff; animation: scroll 1.8s infinite; }
@keyframes scroll { 0% { transform: translateY(-5px); opacity: 0; } 40% { opacity: .8; } 100% { transform: translateY(7px); opacity: 0; } }

.features { max-width: var(--max); margin: auto; padding: 150px 24px; }
.section-heading { max-width: 700px; }
h2 { margin: 0; font-size: clamp(40px, 5vw, 72px); line-height: 1.05; letter-spacing: -.055em; font-weight: 600; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; margin-top: 90px; border-top: 1px solid var(--line); }
.feature { min-height: 250px; padding: 28px 40px 20px 0; border-right: 1px solid var(--line); }
.feature + .feature { padding-left: 40px; }
.feature:last-child { border-right: 0; }
.feature-index { color: #5e6671; font-size: 11px; font-variant-numeric: tabular-nums; }
.feature h3 { margin: 72px 0 15px; font-size: 22px; font-weight: 560; letter-spacing: -.025em; }
.feature p { max-width: 290px; color: var(--muted); font-size: 15px; line-height: 1.75; margin: 0; }

.story { max-width: var(--max); margin: 0 auto 180px; display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: 6%; padding: 0 24px; }
.story-image { width: min(100%, 540px); aspect-ratio: 1; margin: 0; justify-self: center; }
.story-image img { display: block; width: 100%; height: 100%; object-fit: contain; }
.story-copy h2 { font-size: clamp(38px, 3.8vw, 56px); word-break: keep-all; }
.story-copy > p:last-child { margin: 30px 0 0; color: var(--muted); font-size: 16px; line-height: 1.9; }

.closing { min-height: 680px; display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 100px 24px; background: radial-gradient(circle at 50% 65%, rgba(24, 101, 181, .16), transparent 35%); }
.closing-icon { width: clamp(144px, 10vw, 180px); height: auto; border-radius: 23%; box-shadow: 0 25px 60px rgba(0, 0, 0, .55); }
.closing h2 { max-width: 1100px; margin: 34px auto; word-break: keep-all; }

footer { max-width: var(--max); margin: auto; min-height: 110px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 24px; padding: 25px 24px; border-top: 1px solid var(--line); color: #737a84; font-size: 12px; }
footer nav { display: flex; gap: 24px; }
footer nav a:hover { color: #fff; }
footer p { text-align: right; }
.footer-brand { color: #a7adb6; font-size: 13px; }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s ease, transform .8s ease; }
.reveal.visible { opacity: 1; transform: none; }

.legal { max-width: 760px; min-height: calc(100vh - 110px); margin: auto; padding: 150px 24px 100px; }
.legal h1 { font-size: clamp(44px, 7vw, 76px); }
.legal .updated { margin: 18px 0 60px; color: #6d747e; font-size: 13px; }
.legal section { margin: 42px 0; }
.legal h2 { margin-bottom: 14px; font-size: 22px; letter-spacing: -.02em; }
.legal p, .legal li { color: #a4abb5; font-size: 15px; line-height: 1.8; }
.legal a { color: var(--blue); }
.support-card { margin-top: 50px; padding: 30px; border: 1px solid var(--line); background: var(--surface); }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; text-align: center; padding-top: 130px; }
  .hero-copy { max-width: 700px; margin: auto; }
  .device-wrap { transform: none; }
  .device { width: min(760px, 92vw); }
  .feature-grid { grid-template-columns: 1fr; }
  .feature, .feature + .feature { min-height: 0; padding: 30px 0 35px; border-right: 0; border-bottom: 1px solid var(--line); }
  .feature:last-child { border-bottom: 0; }
  .feature h3 { margin-top: 35px; }
  .story { grid-template-columns: 1fr; gap: 55px; }
}

@media (max-width: 680px) {
  .nav { height: 66px; padding: 0 18px; }
  .brand span { display: none; }
  .hero { min-height: auto; gap: 70px; padding: 130px 18px 100px; }
  h1 { font-size: clamp(54px, 17vw, 76px); }
  .hero-description br { display: none; }
  .device { width: calc(100vw - 24px); margin-left: 0; border-radius: 25px; padding: 6px; }
  .device-screen { border-radius: 19px; }
  .scroll-cue { display: none; }
  .features { padding: 110px 22px; }
  .feature-grid { margin-top: 60px; }
  .story { grid-template-columns: 1fr; gap: 55px; margin-bottom: 100px; padding: 0 22px; }
  .story-copy h2, .closing h2 { word-break: normal; }
  .story-image { width: min(100%, 480px); }
  .closing { min-height: 600px; }
  footer { grid-template-columns: 1fr auto; }
  footer nav { grid-row: 2; grid-column: 1 / -1; }
  footer p { text-align: right; }
}

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