:root {
  color-scheme: light;
  --bg: #f4f8fb;
  --surface: #ffffff;
  --surface-soft: #eef6fb;
  --ink: #132235;
  --muted: #536677;
  --subtle: #7c8d9a;
  --line: #dcecf6;
  --blue: #2388ee;
  --blue-dark: #1675d1;
  --blue-soft: #edf7ff;
  --teal: #11b883;
  --teal-soft: #eafbf5;
  --orange: #f28a16;
  --orange-soft: #fff4e6;
  --red: #ef4d47;
  --shadow: 0 24px 70px rgb(19 34 53 / 0.14);
  --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;
  overflow-x: hidden;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 18% 12%, rgb(17 184 131 / 0.14), transparent 28%),
    radial-gradient(circle at 84% 4%, rgb(35 136 238 / 0.16), transparent 30%),
    linear-gradient(180deg, #f8fcff 0%, var(--bg) 52%, #ffffff 100%);
}

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

p,
h1,
h2,
strong,
summary,
li {
  overflow-wrap: break-word;
}

.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; }

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgb(248 252 255 / 0.88);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgb(220 236 246 / 0.78);
}

.topbar-inner {
  min-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;
  letter-spacing: 0;
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  box-shadow: 0 10px 26px rgb(35 136 238 / 0.22);
}

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

.nav a {
  text-decoration: none;
  font-weight: 700;
}

.nav a:hover { color: var(--ink); }

.lang-switch {
  border: 1px solid rgb(19 34 53 / 0.18);
  background: var(--surface);
  color: var(--ink);
  border-radius: 999px;
  padding: 7px 13px;
  min-height: 38px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 8px 22px rgb(19 34 53 / 0.08);
}

.lang-switch:focus-visible,
.btn:focus-visible,
.nav a:focus-visible,
.footer a:focus-visible {
  outline: 3px solid rgb(35 136 238 / 0.32);
  outline-offset: 3px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1fr);
  gap: clamp(36px, 6vw, 88px);
  align-items: center;
  padding: clamp(54px, 7vw, 92px) 0 72px;
}

.hero-copy,
.hero-visual {
  min-width: 0;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--blue-dark);
  font-weight: 850;
}

h1 {
  margin: 0;
  max-width: 780px;
  font-size: clamp(56px, 8vw, 96px);
  line-height: 0.98;
  letter-spacing: 0;
}

.lead {
  margin: 24px 0 0;
  max-width: 720px;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 23px);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 22px;
  border: 1.5px solid var(--blue-dark);
  border-radius: 999px;
  text-decoration: none;
  font-weight: 850;
  background: var(--blue);
  color: #ffffff;
  box-shadow: 0 12px 26px rgb(35 136 238 / 0.2);
}

.btn.secondary {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--line);
  box-shadow: 0 12px 26px rgb(19 34 53 / 0.08);
}

.hero-visual {
  position: relative;
  justify-self: center;
  width: min(100%, 520px);
  min-height: 610px;
  display: grid;
  place-items: center;
}

.phone-frame {
  width: min(100%, 360px);
  min-height: 700px;
  border: 10px solid #172538;
  border-radius: 44px;
  background: linear-gradient(180deg, #f9fdff, #eef7fc);
  box-shadow: var(--shadow);
  padding: 18px;
  overflow: hidden;
  position: relative;
}

.phone-frame::before {
  content: "";
  position: absolute;
  top: 10px;
  left: 50%;
  width: 86px;
  height: 24px;
  transform: translateX(-50%);
  border-radius: 999px;
  background: #172538;
  z-index: 2;
}

.phone-status {
  display: flex;
  justify-content: space-between;
  margin: 18px 4px 20px;
  color: var(--ink);
  font-size: 13px;
  font-weight: 800;
}

.phone-title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.phone-title img {
  width: 48px;
  height: 48px;
  border-radius: 13px;
  box-shadow: 0 10px 22px rgb(35 136 238 / 0.24);
}

.phone-title strong,
.phone-title small {
  display: block;
}

.phone-title strong {
  font-size: 18px;
}

.phone-title small {
  color: var(--subtle);
  font-weight: 700;
}

.storage-card {
  display: grid;
  grid-template-columns: 112px minmax(0, 1fr);
  align-items: center;
  gap: 16px;
  padding: 18px;
  border-radius: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: 0 16px 34px rgb(19 34 53 / 0.08);
}

.ring {
  width: 112px;
  aspect-ratio: 1;
  border-radius: 50%;
  background:
    radial-gradient(circle, var(--surface) 0 53%, transparent 54%),
    conic-gradient(var(--blue) 0 42%, var(--teal) 42% 68%, var(--orange) 68% 82%, #e6eef4 82% 100%);
}

.storage-card .label,
.storage-card small {
  display: block;
  color: var(--subtle);
  font-weight: 760;
}

.storage-card strong {
  display: block;
  font-size: 42px;
  line-height: 1;
  margin: 7px 0;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 12px;
}

.metric-grid div {
  min-height: 90px;
  padding: 15px;
  border-radius: 18px;
  background: var(--surface);
  border: 1px solid var(--line);
}

.metric-grid strong,
.metric-grid span {
  display: block;
}

.metric-grid strong {
  font-size: 21px;
  margin-bottom: 5px;
}

.metric-grid span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 760;
}

.mini-actions {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}

.mini-actions span {
  display: block;
  padding: 15px 17px;
  border-radius: 18px;
  background: #ffffff;
  border: 1px solid var(--line);
  color: var(--ink);
  font-weight: 850;
}

.hero-card {
  position: absolute;
  width: 210px;
  border-radius: 24px;
  filter: drop-shadow(0 20px 35px rgb(19 34 53 / 0.14));
}

.hero-card-one {
  right: 0;
  top: 42px;
  transform: rotate(6deg);
}

.hero-card-two {
  left: 0;
  bottom: 32px;
  transform: rotate(-7deg);
}

.section {
  padding: 76px 0;
  border-top: 1px solid rgb(220 236 246 / 0.86);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 460px) minmax(0, 1fr);
  gap: 34px;
  align-items: end;
  margin-bottom: 30px;
}

h2 {
  margin: 0;
  font-size: clamp(34px, 4.6vw, 58px);
  line-height: 1.02;
  letter-spacing: 0;
}

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

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

.feature-card {
  padding: 24px;
  min-height: 226px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgb(255 255 255 / 0.92);
  box-shadow: 0 12px 28px rgb(19 34 53 / 0.06);
}

.feature-card.wide {
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  align-items: center;
  gap: 18px;
  grid-column: span 2;
  background: linear-gradient(145deg, #ffffff, var(--blue-soft));
}

.feature-card img {
  width: 58px;
  height: 58px;
  object-fit: contain;
  margin-bottom: 20px;
}

.feature-card.wide img {
  width: 170px;
  height: auto;
  margin: 0;
}

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

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

.flow-section {
  background: linear-gradient(180deg, transparent, rgb(255 255 255 / 0.64));
}

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

.flow-step {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: 0 12px 28px rgb(19 34 53 / 0.06);
}

.flow-step > span:first-child {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: var(--teal-soft);
  color: var(--teal);
  font-weight: 900;
  margin-bottom: 18px;
}

.flow-step strong {
  display: block;
  font-size: 24px;
  margin-bottom: 8px;
}

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

.privacy-band {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(280px, 0.92fr);
  gap: 28px;
  padding: clamp(28px, 4vw, 42px);
  border: 1.5px solid rgb(19 34 53 / 0.18);
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgb(237 247 255 / 0.96), rgb(234 251 245 / 0.96)),
    var(--surface-soft);
  box-shadow: 0 20px 52px rgb(19 34 53 / 0.08);
}

.privacy-band p:not(.eyebrow) {
  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: 15px 17px;
  border: 1px solid rgb(220 236 246 / 0.96);
  border-radius: 16px;
  background: rgb(255 255 255 / 0.88);
  font-weight: 820;
}

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

.plan {
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 12px 28px rgb(19 34 53 / 0.06);
}

.plan.featured {
  border-color: rgb(17 184 131 / 0.42);
  background: linear-gradient(145deg, var(--teal-soft), #ffffff);
}

.plan h3 {
  margin: 0 0 16px;
  font-size: 30px;
}

.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(--surface);
  box-shadow: 0 10px 24px rgb(19 34 53 / 0.05);
}

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

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

.footer {
  min-height: 104px;
  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;
  font-weight: 720;
}

@media (max-width: 980px) {
  .hero {
    grid-template-columns: 1fr;
    padding-top: 46px;
  }

  .hero-visual {
    min-height: 590px;
  }

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

  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .shell {
    width: min(calc(100% - 28px), var(--max));
  }

  .topbar-inner {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
  }

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

  h1 {
    font-size: 54px;
  }

  .hero-visual {
    max-width: min(calc(100vw - 28px), 362px);
    width: min(calc(100vw - 28px), 362px);
    justify-self: start;
    min-height: auto;
  }

  .hero-copy {
    max-width: min(calc(100vw - 28px), 362px);
    width: min(calc(100vw - 28px), 362px);
  }

  .phone-frame {
    width: min(100%, 320px);
    min-height: 628px;
    border-width: 9px;
    padding: 16px;
    margin: 0 auto;
  }

  .hero-card {
    display: none;
  }

  .feature-grid,
  .flow {
    grid-template-columns: 1fr;
  }

  .feature-card.wide {
    display: block;
    grid-column: auto;
  }

  .feature-card.wide img {
    width: min(100%, 220px);
    margin-bottom: 18px;
  }

  .storage-card {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 13px;
    padding: 16px;
  }

  .ring {
    width: 88px;
  }

  .storage-card strong {
    font-size: 38px;
  }

  .metric-grid strong {
    font-size: 20px;
  }

  .footer {
    flex-direction: column;
    align-items: flex-start;
    padding: 26px 0;
  }
}