:root {
  color-scheme: dark;
  --ink: #f4f7ff;
  --muted: #aab7d4;
  --muted-strong: #c8d1e6;
  --paper: #07182f;
  --paper-raised: #0d2342;
  --line: rgba(190, 211, 247, .16);
  --aqua: #5fe2d0;
  --blue: #7184ff;
  --blue-dark: #4056da;
  --warning: #ffd38c;
  --max-width: 74rem;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--paper); }
body {
  margin: 0;
  min-width: 20rem;
  color: var(--ink);
  background:
    radial-gradient(48rem 32rem at 92% -12%, rgba(86, 104, 255, .30), transparent 70%),
    radial-gradient(38rem 26rem at -8% 24%, rgba(32, 195, 183, .18), transparent 68%),
    var(--paper);
  font-size: 1rem;
  line-height: 1.6;
}

a { color: inherit; text-underline-offset: .18em; }
a:focus-visible, button:focus-visible { outline: .18rem solid var(--aqua); outline-offset: .25rem; }
button { font: inherit; }
img { display: block; max-width: 100%; }

.site-shell { overflow: clip; }
.container { width: min(calc(100% - 2.5rem), var(--max-width)); margin-inline: auto; }
.narrow { width: min(calc(100% - 2.5rem), 52rem); margin-inline: auto; }

.skip-link {
  position: fixed; z-index: 10; top: .75rem; left: .75rem; padding: .55rem .8rem;
  border-radius: .5rem; background: var(--ink); color: #041327; transform: translateY(-180%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky; z-index: 5; top: 0; border-bottom: 1px solid transparent;
  backdrop-filter: blur(1.2rem); background: rgba(7, 24, 47, .76);
}
.site-header.is-scrolled { border-color: var(--line); }
.nav-wrap { min-height: 4.75rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.brand { display: inline-flex; align-items: center; gap: .72rem; color: var(--ink); text-decoration: none; font-weight: 760; letter-spacing: -.02em; }
.brand img { width: 2.1rem; height: 2.1rem; border-radius: .64rem; box-shadow: 0 .4rem 1.25rem rgba(0, 0, 0, .24); }
.brand span { font-size: 1.03rem; }
.site-nav { display: flex; align-items: center; flex-wrap: wrap; justify-content: flex-end; gap: .2rem; }
.site-nav a, .language-toggle {
  padding: .46rem .58rem; border: 0; border-radius: .55rem; background: transparent; color: var(--muted-strong); font-size: .9rem; text-decoration: none; cursor: pointer;
}
.site-nav a:hover, .language-toggle:hover { color: var(--ink); background: rgba(255,255,255,.07); }
.language-toggle { border: 1px solid var(--line); margin-left: .18rem; }

.hero { padding: clamp(4.3rem, 9vw, 8rem) 0 3rem; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.06fr) minmax(19rem, .76fr); align-items: center; gap: clamp(2rem, 7vw, 6rem); }
.eyebrow { display: inline-flex; align-items: center; gap: .52rem; margin: 0 0 1.15rem; color: var(--aqua); font-size: .85rem; font-weight: 760; letter-spacing: .08em; text-transform: uppercase; }
.eyebrow::before { content: ""; display: inline-block; width: .55rem; height: .55rem; border-radius: 50%; background: currentColor; box-shadow: 0 0 1rem currentColor; }
h1, h2, h3 { margin: 0; font-weight: 780; letter-spacing: -.045em; line-height: 1.08; }
h1 { max-width: 14ch; font-size: clamp(3rem, 6.4vw, 5.85rem); }
h2 { font-size: clamp(2rem, 3.7vw, 3.2rem); }
h3 { font-size: clamp(1.22rem, 2.2vw, 1.48rem); letter-spacing: -.03em; }
.hero h1 + h1 { margin-top: .24rem; }
.lead { max-width: 39rem; margin: 1.5rem 0 0; color: var(--muted-strong); font-size: clamp(1.08rem, 1.7vw, 1.28rem); line-height: 1.7; }
.lead + .lead { margin-top: .5rem; }
.button-row { display: flex; flex-wrap: wrap; align-items: center; gap: .75rem; margin-top: 2rem; }
.button {
  display: inline-flex; align-items: center; justify-content: center; min-height: 3.1rem; padding: .78rem 1rem;
  border: 1px solid transparent; border-radius: .85rem; background: linear-gradient(135deg, var(--blue), #8594ff); color: #fff;
  box-shadow: 0 1rem 2rem rgba(65, 82, 220, .25); font-weight: 720; text-decoration: none;
}
.button:hover { transform: translateY(-.08rem); box-shadow: 0 1.2rem 2.4rem rgba(65, 82, 220, .34); }
.button.secondary { border-color: var(--line); background: rgba(255,255,255,.045); box-shadow: none; color: var(--ink); }
.hero-note { margin: 1.1rem 0 0; color: var(--muted); font-size: .9rem; }

.device-stage { position: relative; justify-self: center; width: min(100%, 22rem); }
.device-stage::before { content: ""; position: absolute; z-index: -1; width: 88%; aspect-ratio: 1; left: 6%; top: 10%; border-radius: 50%; background: rgba(91, 224, 208, .23); filter: blur(2.5rem); }
.device { overflow: hidden; border: .54rem solid #020c1c; border-radius: 2.65rem; background: #f4f7ff; box-shadow: 0 2rem 4rem rgba(0, 0, 0, .42), 0 0 0 1px rgba(255,255,255,.22); }
.device img { width: 100%; height: auto; }
.floating-note { position: absolute; right: -2rem; bottom: 9%; width: 12.8rem; padding: .86rem .96rem; border: 1px solid rgba(255,255,255,.18); border-radius: 1rem; background: rgba(13, 35, 66, .91); box-shadow: 0 1.2rem 2.5rem rgba(0, 0, 0, .23); backdrop-filter: blur(1rem); }
.floating-note strong { display: block; color: var(--aqua); font-size: .87rem; }
.floating-note span { display: block; margin-top: .18rem; color: var(--muted-strong); font-size: .79rem; line-height: 1.35; }

.trust-strip { margin-top: clamp(2rem, 4vw, 4.6rem); padding: 1rem 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.trust-strip ul { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; padding: 0; margin: 0; list-style: none; }
.trust-strip li { color: var(--muted-strong); font-size: .92rem; }
.trust-strip b { display: block; color: var(--ink); font-size: .96rem; }

section { padding: clamp(4.5rem, 9vw, 7.5rem) 0; }
.section-kicker { color: var(--aqua); font-size: .86rem; font-weight: 750; letter-spacing: .075em; text-transform: uppercase; }
.section-heading { max-width: 31rem; margin-top: .8rem; }
.section-intro { max-width: 43rem; margin: 1.15rem 0 0; color: var(--muted-strong); font-size: 1.08rem; }

.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; margin-top: 2.7rem; }
.step { min-height: 15.5rem; padding: 1.35rem; border: 1px solid var(--line); border-radius: 1.2rem; background: linear-gradient(145deg, rgba(255,255,255,.065), rgba(255,255,255,.018)); }
.step-index { display: grid; place-items: center; width: 2.25rem; height: 2.25rem; margin-bottom: 2rem; border-radius: .7rem; background: rgba(113,132,255,.19); color: #b7c1ff; font-weight: 760; }
.step p { margin: .7rem 0 0; color: var(--muted); font-size: .94rem; }

.recording { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: rgba(4, 16, 35, .45); }
.recording-grid { display: grid; grid-template-columns: .86fr 1.14fr; gap: clamp(2rem, 7vw, 6rem); align-items: center; }
.recording-card { overflow: hidden; border: 1px solid var(--line); border-radius: 1.45rem; background: #eff3ff; box-shadow: 0 1.6rem 3.6rem rgba(0,0,0,.22); }
.recording-card img { width: 100%; }
.list { display: grid; gap: 1rem; padding: 0; margin: 1.7rem 0 0; list-style: none; }
.list li { display: grid; grid-template-columns: 1.45rem 1fr; gap: .7rem; color: var(--muted-strong); }
.list li::before { content: "✓"; display: grid; place-items: center; width: 1.45rem; height: 1.45rem; margin-top: .13rem; border-radius: 50%; background: rgba(95,226,208,.15); color: var(--aqua); font-size: .8rem; font-weight: 800; }
.callout { margin-top: 1.6rem; padding: 1rem 1.1rem; border-left: .22rem solid var(--warning); border-radius: 0 .8rem .8rem 0; background: rgba(255,211,140,.08); color: #ffdfad; font-size: .93rem; }

.privacy-glance { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin-top: 2.7rem; }
.glance-card { padding: 1.5rem; border-radius: 1.25rem; background: var(--paper-raised); border: 1px solid var(--line); }
.glance-icon { display: grid; place-items: center; width: 2.65rem; height: 2.65rem; margin-bottom: 1.3rem; border-radius: .85rem; background: rgba(95,226,208,.13); color: var(--aqua); font-size: 1.3rem; }
.glance-card p { margin: .75rem 0 0; color: var(--muted); font-size: .94rem; }

.faq { display: grid; grid-template-columns: minmax(0, .82fr) minmax(0, 1.18fr); gap: clamp(2rem, 8vw, 7rem); border-top: 1px solid var(--line); }
.faq-list { display: grid; gap: .75rem; }
details { padding: 1rem 1.1rem; border: 1px solid var(--line); border-radius: .9rem; background: rgba(255,255,255,.035); }
summary { cursor: pointer; color: var(--ink); font-weight: 700; }
details p { margin: .75rem 0 0; color: var(--muted); }

.site-footer { margin-top: clamp(3rem, 8vw, 7rem); padding: 2.6rem 0 2.2rem; border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 2rem; }
.footer-title { margin: 0 0 .55rem; color: var(--muted); font-size: .8rem; font-weight: 750; letter-spacing: .08em; text-transform: uppercase; }
.footer-copy, .site-footer li { color: var(--muted); font-size: .9rem; }
.site-footer ul { display: grid; gap: .45rem; padding: 0; margin: 0; list-style: none; }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .8rem; margin-top: 2.2rem; padding-top: 1.2rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .81rem; }

.legal-header { padding: clamp(3.5rem, 8vw, 6rem) 0 2.4rem; border-bottom: 1px solid var(--line); }
.legal-header h1 { max-width: 17ch; font-size: clamp(2.55rem, 5.2vw, 4.4rem); }
.legal-header p { max-width: 44rem; margin: 1.15rem 0 0; color: var(--muted-strong); font-size: 1.08rem; }
.legal-meta { display: flex; flex-wrap: wrap; gap: .75rem 1.5rem; margin-top: 1.4rem; color: var(--muted); font-size: .9rem; }
.legal { padding-top: 3.2rem; }
.legal section { padding: 0 0 2.65rem; }
.legal h2 { margin-bottom: 1rem; font-size: clamp(1.45rem, 2.8vw, 2rem); }
.legal h3 { margin: 1.45rem 0 .6rem; font-size: 1.14rem; }
.legal p, .legal li { color: var(--muted-strong); }
.legal ul { padding-left: 1.25rem; }
.legal li + li { margin-top: .55rem; }
.legal .notice { padding: 1rem 1.15rem; border: 1px solid rgba(255, 211, 140, .33); border-radius: .9rem; background: rgba(255, 211, 140, .075); color: #ffe3b2; }
.contact-card { padding: 1.3rem; border: 1px solid var(--line); border-radius: 1rem; background: var(--paper-raised); }
.contact-card p { margin: .4rem 0 0; }

[hidden] { display: none !important; }

@media (max-width: 58rem) {
  .hero-grid, .recording-grid, .faq { grid-template-columns: 1fr; }
  .hero { padding-top: 4.2rem; }
  .device-stage { width: min(100%, 20rem); grid-row: 1; }
  .floating-note { right: -1rem; }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .privacy-glance { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 42rem) {
  .container, .narrow { width: min(calc(100% - 1.5rem), var(--max-width)); }
  .site-header { position: relative; }
  .nav-wrap { padding: .72rem 0; align-items: flex-start; }
  .site-nav { justify-content: flex-end; gap: .05rem; }
  .site-nav a { display: none; }
  .site-nav a:last-of-type { display: inline-flex; }
  h1 { font-size: clamp(2.68rem, 13vw, 4rem); }
  .trust-strip ul { grid-template-columns: 1fr; gap: .75rem; }
  .steps { grid-template-columns: 1fr; }
  .step { min-height: auto; }
  .step-index { margin-bottom: 1.25rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .floating-note { right: -.35rem; bottom: 4%; width: 11rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button { transition: none; }
}