:root {
  color-scheme: light dark;
  --bg: #f7f8fc;
  --bg-strong: #eef0f8;
  --surface: rgba(255, 255, 255, .78);
  --surface-solid: #ffffff;
  --surface-soft: #f1f1fb;
  --text: #191a25;
  --muted: #686b7d;
  --line: rgba(50, 52, 77, .12);
  --line-strong: rgba(83, 70, 224, .2);
  --primary: #6757f5;
  --primary-strong: #5141e7;
  --primary-soft: #ece9ff;
  --blue: #4d8df7;
  --green: #1c9d72;
  --shadow-sm: 0 12px 40px rgba(35, 28, 87, .08);
  --shadow-lg: 0 32px 90px rgba(44, 31, 126, .18);
  --radius-sm: 14px;
  --radius-md: 22px;
  --radius-lg: 32px;
  --container: 1160px;
  --header-height: 72px;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #11121a;
    --bg-strong: #171824;
    --surface: rgba(29, 30, 43, .82);
    --surface-solid: #1d1e2b;
    --surface-soft: #232435;
    --text: #f4f3fb;
    --muted: #a7a9bb;
    --line: rgba(220, 219, 245, .12);
    --line-strong: rgba(154, 140, 255, .28);
    --primary: #9789ff;
    --primary-strong: #b1a7ff;
    --primary-soft: #2f2a59;
    --blue: #74a6ff;
    --green: #64d2a9;
    --shadow-sm: 0 14px 44px rgba(0, 0, 0, .22);
    --shadow-lg: 0 34px 100px rgba(0, 0, 0, .4);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-height) + 24px); }

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  color: var(--text);
  background:
    radial-gradient(circle at 82% 9%, rgba(108, 85, 247, .11), transparent 25rem),
    radial-gradient(circle at 6% 33%, rgba(77, 141, 247, .08), transparent 24rem),
    var(--bg);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }
a { color: inherit; }
button, input, textarea, select { font: inherit; }

html[data-lang="en"] [data-lang-copy="zh"],
html[data-lang="zh"] [data-lang-copy="en"] { display: none !important; }

.skip-link {
  position: fixed;
  z-index: 1000;
  left: 16px;
  top: -100px;
  padding: 10px 16px;
  color: #fff;
  background: var(--primary-strong);
  border-radius: 10px;
  transition: top .2s ease;
}
.skip-link:focus { top: 16px; }

.container { width: min(var(--container), calc(100% - 48px)); margin-inline: auto; }
.section { padding: 112px 0; }

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  height: var(--header-height);
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(18px) saturate(150%);
}
.nav-shell { height: 100%; display: flex; align-items: center; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); font-size: 19px; font-weight: 780; letter-spacing: -.02em; text-decoration: none; }
.brand img { border-radius: 10px; box-shadow: 0 5px 14px rgba(87, 64, 238, .2); }
.nav-links { display: flex; align-items: center; gap: 28px; margin-left: auto; }
.nav-links a, .footer-links a { color: var(--muted); font-size: 14px; font-weight: 650; text-decoration: none; transition: color .2s ease; }
.nav-links a:hover, .footer-links a:hover { color: var(--text); }
.nav-cta {
  min-width: 76px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 15px;
  color: #fff;
  background: linear-gradient(135deg, #6c5cf7, #7e52ec);
  border-radius: 999px;
  box-shadow: 0 8px 20px rgba(94, 70, 235, .2);
  font-size: 13px;
  font-weight: 760;
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(94, 70, 235, .28); }
.language-switch {
  min-width: 58px;
  height: 36px;
  padding: 0 13px;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 750;
  transition: border-color .2s ease, transform .2s ease, background .2s ease;
}
.language-switch:hover { border-color: var(--line-strong); background: var(--surface-solid); transform: translateY(-1px); }

.hero { min-height: calc(100vh - var(--header-height)); display: grid; align-items: center; padding: 80px 0 92px; }
.hero-grid { display: grid; grid-template-columns: minmax(0, .9fr) minmax(500px, 1.1fr); gap: clamp(48px, 7vw, 92px); align-items: center; }
.eyebrow, .section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--primary-strong);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px color-mix(in srgb, var(--green) 15%, transparent); }
h1, h2, h3, p { margin-top: 0; }
h1 { margin: 23px 0 24px; font-size: clamp(48px, 5.5vw, 76px); line-height: 1.02; letter-spacing: -.055em; font-weight: 820; }
h1 em { color: var(--primary); font-style: normal; }
.hero-lede { max-width: 610px; margin-bottom: 32px; color: var(--muted); font-size: clamp(18px, 2vw, 21px); line-height: 1.65; }
.hero-actions { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 14px;
  font-size: 14px;
  font-weight: 760;
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.button.primary { color: #fff; background: linear-gradient(135deg, #6c5cf7, #7e52ec); box-shadow: 0 13px 30px rgba(94, 70, 235, .25); }
.button.secondary { color: var(--text); background: var(--surface); border-color: var(--line); }
.button:not(.disabled):hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.button.disabled { cursor: default; opacity: .82; }
.compatibility { margin: 18px 0 0; color: var(--muted); font-size: 13px; font-weight: 600; }

.hero-visual { position: relative; min-width: 0; padding: 35px 0 40px; }
.browser-card { position: relative; z-index: 3; overflow: hidden; background: var(--surface-solid); border: 1px solid rgba(118, 103, 226, .2); border-radius: 24px; box-shadow: var(--shadow-lg); transform: perspective(1200px) rotateY(-2deg) rotateX(1deg); }
.browser-bar { height: 42px; display: grid; grid-template-columns: 70px 1fr 70px; align-items: center; padding: 0 14px; border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--surface-solid) 92%, var(--primary-soft)); }
.traffic-lights { display: flex; gap: 6px; }
.traffic-lights span { width: 8px; height: 8px; border-radius: 50%; background: #d4d5de; }
.traffic-lights span:nth-child(1) { background: #ff7f73; }
.traffic-lights span:nth-child(2) { background: #f6c85f; }
.traffic-lights span:nth-child(3) { background: #60c88a; }
.address-pill { min-width: 0; overflow: hidden; padding: 5px 12px; color: var(--muted); background: var(--surface-soft); border-radius: 8px; font-size: 10px; text-overflow: ellipsis; white-space: nowrap; text-align: center; }
.product-shot { width: 100%; height: auto; }
.ambient { position: absolute; border-radius: 50%; filter: blur(2px); pointer-events: none; }
.ambient-one { width: 300px; height: 300px; right: -80px; top: -30px; background: rgba(112, 79, 245, .18); }
.ambient-two { width: 240px; height: 240px; left: -80px; bottom: -10px; background: rgba(76, 146, 246, .15); }
.floating-note { position: absolute; z-index: 5; display: flex; align-items: center; gap: 10px; min-width: 158px; padding: 11px 14px; color: var(--text); background: color-mix(in srgb, var(--surface-solid) 92%, transparent); border: 1px solid var(--line); border-radius: 15px; box-shadow: var(--shadow-sm); backdrop-filter: blur(16px); }
.floating-note > span:last-child { display: grid; }
.floating-note strong { font-size: 12px; line-height: 1.3; }
.floating-note small { color: var(--muted); font-size: 10px; }
.note-icon { width: 28px; height: 28px; display: grid; place-items: center; color: var(--primary); background: var(--primary-soft); border-radius: 9px; font-size: 17px; font-weight: 800; }
.note-local { left: -34px; bottom: 2px; }
.note-fast { right: -28px; top: 4px; }

.trust-strip { border-block: 1px solid var(--line); background: color-mix(in srgb, var(--surface-solid) 55%, transparent); }
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); }
.trust-grid > div { min-width: 0; padding: 27px 24px; border-left: 1px solid var(--line); }
.trust-grid > div:last-child { border-right: 1px solid var(--line); }
.trust-grid strong, .trust-grid span { display: block; }
.trust-grid strong { margin-bottom: 3px; font-size: 14px; }
.trust-grid span { color: var(--muted); font-size: 12px; }

.section-heading { max-width: 760px; margin-bottom: 48px; }
.section-heading.narrow { max-width: 670px; }
.section-heading.compact { max-width: 400px; margin-bottom: 0; }
.section-heading h2, .privacy-copy h2, .boundary-card h2, .cta-card h2 { margin: 15px 0 0; font-size: clamp(36px, 4.8vw, 58px); line-height: 1.08; letter-spacing: -.045em; }
.step-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.step-card, .feature-card { position: relative; overflow: hidden; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }
.step-card { min-height: 260px; padding: 30px; }
.step-card::after { content: ""; position: absolute; width: 130px; height: 130px; right: -50px; bottom: -62px; background: var(--primary-soft); border-radius: 50%; }
.step-number { color: var(--primary); font-size: 12px; font-weight: 850; letter-spacing: .12em; }
.step-card h3, .feature-card h3 { margin: 36px 0 10px; font-size: 20px; letter-spacing: -.02em; }
.step-card p, .feature-card p { margin-bottom: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }

.features-section { background: linear-gradient(180deg, transparent, color-mix(in srgb, var(--primary-soft) 36%, transparent), transparent); }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feature-card { min-height: 270px; padding: 30px; transition: transform .22s ease, border-color .22s ease; }
.feature-card:hover { transform: translateY(-4px); border-color: var(--line-strong); }
.feature-card h3 { margin-top: 28px; }
.feature-icon { width: 42px; height: 42px; display: grid; place-items: center; color: var(--primary); background: var(--primary-soft); border: 1px solid var(--line-strong); border-radius: 13px; font-size: 21px; font-weight: 800; }

.privacy-grid { display: grid; grid-template-columns: .85fr 1.15fr; gap: clamp(52px, 8vw, 96px); align-items: center; }
.privacy-copy > p { margin: 25px 0; color: var(--muted); font-size: 17px; }
.check-list { display: grid; gap: 12px; margin: 0 0 28px; padding: 0; list-style: none; }
.check-list li { display: flex; align-items: flex-start; gap: 11px; font-size: 14px; font-weight: 630; }
.check-list li > span:first-child { width: 22px; height: 22px; flex: 0 0 auto; display: grid; place-items: center; color: var(--green); background: color-mix(in srgb, var(--green) 13%, transparent); border-radius: 50%; font-size: 12px; }
.text-link { color: var(--primary-strong); font-size: 14px; font-weight: 800; text-decoration: none; }
.privacy-visual { position: relative; padding: 22px; background: linear-gradient(135deg, rgba(100, 84, 245, .17), rgba(77, 141, 247, .12)); border: 1px solid var(--line-strong); border-radius: var(--radius-lg); }
.privacy-visual img { width: 100%; height: auto; border-radius: 18px; box-shadow: var(--shadow-lg); }

.boundary-card { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; padding: clamp(34px, 6vw, 70px); color: #fff; background: linear-gradient(135deg, #342b78, #5b48d6 60%, #3a73d9); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); }
.boundary-card .section-kicker { color: #d8d2ff; }
.boundary-card h2 { margin-bottom: 0; }
.boundary-copy { align-self: end; }
.boundary-copy p { margin: 0 0 20px; color: rgba(255, 255, 255, .78); }
.boundary-copy p:last-child { margin-bottom: 0; }

.faq-grid { display: grid; grid-template-columns: .65fr 1.35fr; gap: 72px; align-items: start; }
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { position: relative; padding: 23px 46px 23px 0; cursor: pointer; list-style: none; font-size: 17px; font-weight: 720; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 6px; top: 20px; color: var(--primary); font-size: 24px; font-weight: 400; line-height: 1; transition: transform .2s ease; }
.faq-list details[open] summary::after { transform: rotate(45deg); }
.faq-list details p { max-width: 760px; margin: -6px 0 24px; padding-right: 46px; color: var(--muted); }

.final-cta { padding-top: 70px; }
.cta-card { padding: clamp(50px, 8vw, 92px) 28px; text-align: center; background: linear-gradient(180deg, var(--surface-solid), var(--surface-soft)); border: 1px solid var(--line); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); }
.cta-card > img { margin: 0 auto 22px; border-radius: 17px; box-shadow: 0 13px 30px rgba(94, 70, 235, .22); }
.cta-card h2 { margin-top: 0; }
.cta-card > p { margin: 20px auto 28px; color: var(--muted); }
.hero-actions.centered { justify-content: center; }

.site-footer { padding: 30px 0 42px; border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 1fr auto 1fr; gap: 24px; align-items: center; }
.footer-brand { font-size: 16px; }
.footer-links { display: flex; align-items: center; gap: 24px; }
.footer-grid > p { margin: 0; color: var(--muted); font-size: 12px; text-align: right; }

.legal-hero { padding: 72px 0 38px; }
.legal-hero h1 { margin-bottom: 14px; font-size: clamp(42px, 6vw, 68px); }
.legal-hero p { max-width: 720px; color: var(--muted); font-size: 17px; }
.legal-layout { display: grid; grid-template-columns: 220px minmax(0, 760px); gap: 64px; align-items: start; padding-bottom: 112px; }
.legal-nav { position: sticky; top: calc(var(--header-height) + 30px); display: grid; gap: 7px; }
.legal-nav a { padding: 8px 12px; color: var(--muted); border-radius: 10px; font-size: 13px; font-weight: 680; text-decoration: none; }
.legal-nav a:hover { color: var(--text); background: var(--surface-soft); }
.legal-article { padding: clamp(28px, 5vw, 48px); background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }
.legal-article h2 { margin: 2.2em 0 .65em; font-size: 25px; letter-spacing: -.025em; }
.legal-article h2:first-child { margin-top: 0; }
.legal-article h3 { margin: 1.8em 0 .55em; font-size: 18px; }
.legal-article p, .legal-article li { color: var(--muted); }
.legal-article li + li { margin-top: 7px; }
.legal-article code { padding: 2px 6px; color: var(--text); background: var(--surface-soft); border: 1px solid var(--line); border-radius: 6px; font-size: .88em; }
.legal-meta { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 20px; }
.legal-badge { display: inline-flex; padding: 5px 10px; color: var(--primary-strong); background: var(--primary-soft); border-radius: 999px; font-size: 12px; font-weight: 760; }
.support-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-bottom: 54px; }
.support-card { padding: 28px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); }
.support-card h2 { margin: 0 0 8px; font-size: 19px; }
.support-card p { margin-bottom: 18px; color: var(--muted); font-size: 14px; }
.support-card a { color: var(--primary-strong); font-size: 14px; font-weight: 760; text-decoration: none; }

:focus-visible { outline: 3px solid color-mix(in srgb, var(--primary) 42%, transparent); outline-offset: 3px; }

@media (max-width: 980px) {
  .hero { min-height: auto; }
  .hero-grid, .privacy-grid { grid-template-columns: 1fr; }
  .hero-grid { gap: 48px; }
  .hero-copy { max-width: 780px; }
  .hero-visual { max-width: 780px; margin-inline: auto; }
  .trust-grid { grid-template-columns: repeat(2, 1fr); }
  .trust-grid > div:nth-child(2) { border-right: 1px solid var(--line); }
  .trust-grid > div:nth-child(n+3) { border-top: 1px solid var(--line); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .faq-grid { grid-template-columns: 1fr; gap: 38px; }
  .section-heading.compact { max-width: 680px; }
  .legal-layout { grid-template-columns: 1fr; gap: 24px; }
  .legal-nav { position: static; display: flex; flex-wrap: wrap; }
}

@media (max-width: 720px) {
  :root { --header-height: 64px; }
  .container { width: min(100% - 30px, var(--container)); }
  .section { padding: 80px 0; }
  .nav-shell { gap: 14px; }
  .nav-links { display: none; }
  .nav-cta { margin-left: auto; min-width: 68px; padding-inline: 13px; }
  .hero { padding: 60px 0 74px; }
  .hero-grid { grid-template-columns: minmax(0, 1fr); }
  h1 { font-size: clamp(43px, 13vw, 60px); }
  .hero-lede { font-size: 17px; }
  .hero-actions { align-items: stretch; flex-direction: column; }
  .button { width: 100%; }
  .hero-visual { width: 100%; padding: 22px 0 52px; }
  .ambient-one { right: 0; }
  .ambient-two { left: 0; }
  .browser-card { border-radius: 18px; transform: none; }
  .browser-bar { height: 34px; grid-template-columns: 56px 1fr 56px; }
  .note-fast { display: none; }
  .note-local { left: 15px; bottom: 0; }
  .trust-grid { grid-template-columns: 1fr 1fr; }
  .trust-grid > div { padding: 21px 16px; }
  .step-grid, .feature-grid, .support-grid { grid-template-columns: 1fr; }
  .step-card, .feature-card { min-height: auto; }
  .boundary-card { grid-template-columns: 1fr; gap: 34px; }
  .section-heading h2, .privacy-copy h2, .boundary-card h2, .cta-card h2 { font-size: clamp(34px, 10vw, 46px); }
  .footer-grid { grid-template-columns: 1fr; justify-items: start; }
  .footer-grid > p { text-align: left; }
  .legal-hero { padding-top: 52px; }
  .legal-layout { padding-bottom: 80px; }
  .legal-article { padding: 25px 20px; }
}

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