:root {
  color-scheme: light;
  --bg: #ffffff;
  --ink: #111214;
  --muted: #666b73;
  --line: #e8eaee;
  --soft: #f7f9fb;
  --accent: #0a84ff;
  --accent-soft: #eaf4ff;
  --radius: 18px;
  --max: 1160px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", "PingFang SC", "PingFang TC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.55;
}

body { margin: 0; }

a { color: inherit; text-underline-offset: 4px; }

.cn, .en { display: none; }
html[data-lang="zh"] .cn { display: inline; }
html[data-lang="zh"] .cn.block { display: block; }
html[data-lang="en"] .en { display: inline; }
html[data-lang="en"] .en.block { display: block; }
html[data-lang="zh"] .shot-en,
html[data-lang="en"] .shot-zh { display: none; }

.shell {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}

.topbar-inner {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-weight: 850;
}

.brand-icon {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  box-shadow: 0 6px 18px rgba(10, 132, 255, 0.18);
}

.nav {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--muted);
  font-size: 15px;
}

.nav a { text-decoration: none; }

.lang-switch {
  border: 1px solid var(--ink);
  background: var(--bg);
  color: var(--ink);
  border-radius: 999px;
  padding: 7px 12px;
  min-height: 38px;
  font: inherit;
  font-weight: 750;
  cursor: pointer;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(360px, 0.98fr);
  gap: clamp(38px, 6vw, 88px);
  align-items: center;
  padding: clamp(56px, 8vw, 104px) 0 76px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent);
  font-weight: 800;
}

h1 {
  margin: 0;
  max-width: 760px;
  font-size: clamp(48px, 7vw, 88px);
  line-height: 0.98;
  letter-spacing: 0;
}

.lead {
  margin: 24px 0 0;
  max-width: 700px;
  color: var(--muted);
  font-size: clamp(18px, 2.1vw, 24px);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 20px;
  border: 1.5px solid var(--ink);
  border-radius: 999px;
  text-decoration: none;
  font-weight: 800;
  background: var(--ink);
  color: var(--bg);
}

.btn.secondary {
  background: var(--bg);
  color: var(--ink);
  border-color: var(--line);
}

.hero-visual {
  justify-self: center;
  width: min(100%, 520px);
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: linear-gradient(145deg, #f8fbff, #ffffff);
  box-shadow: 0 24px 70px rgba(17, 18, 20, 0.12);
}

.hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 14px;
}

.section {
  padding: 74px 0;
  border-top: 1px solid var(--line);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 430px) minmax(0, 1fr);
  gap: 32px;
  align-items: end;
  margin-bottom: 30px;
}

h2 {
  margin: 0;
  font-size: clamp(32px, 4.2vw, 56px);
  line-height: 1;
  letter-spacing: 0;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.card {
  padding: 24px;
  min-height: 180px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
}

.card strong {
  display: block;
  font-size: 22px;
  margin-bottom: 10px;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.privacy-band {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  gap: 28px;
  padding: 34px;
  border: 1.5px solid var(--ink);
  border-radius: 26px;
  background: var(--soft);
}

.privacy-band p {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.checklist {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.checklist li {
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--bg);
  font-weight: 760;
}

.plans {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.plan {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
}

.plan.featured {
  border-color: rgba(10, 132, 255, 0.45);
  background: var(--accent-soft);
}

.plan h3 {
  margin: 0 0 16px;
  font-size: 28px;
}

.plan ul {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

.plan li { margin: 8px 0; }

.faq {
  display: grid;
  gap: 12px;
}

details {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px 20px;
  background: var(--bg);
}

summary {
  cursor: pointer;
  font-weight: 850;
  font-size: 18px;
}

details p {
  margin: 12px 0 0;
  color: var(--muted);
}

.footer {
  min-height: 96px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.footer-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-links a { text-decoration: none; }

@media (max-width: 860px) {
  .topbar-inner {
    height: auto;
    min-height: 72px;
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
  }

  .nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .hero,
  .section-head,
  .privacy-band,
  .plans {
    grid-template-columns: 1fr;
  }

  .hero { padding-top: 46px; }
  .grid { grid-template-columns: 1fr; }
  .footer { flex-direction: column; align-items: flex-start; padding: 26px 0; }
}