:root {
  color-scheme: light;
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-alt: #f1f4f8;
  --line: #d8dee8;
  --text: #172033;
  --muted: #667085;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --success: #16a34a;
  --warning: #d97706;
  --code: #111827;
  --shadow: 0 22px 56px rgb(15 23 42 / 9%);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Noto Sans SC", "Segoe UI", sans-serif;
  letter-spacing: 0;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(90deg, rgb(37 99 235 / 6%), transparent 34%, rgb(22 163 74 / 5%)),
    linear-gradient(180deg, #ffffff, var(--bg) 42%, #eef3f9);
  content: "";
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 14px 0;
  backdrop-filter: blur(18px);
}

.brand,
.site-header nav,
.hero-actions,
.trust-row,
.site-footer {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-weight: 700;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  box-shadow: 0 10px 24px rgb(37 99 235 / 18%);
}

.site-header nav {
  gap: 4px;
  padding: 5px;
  border: 1px solid rgb(216 222 232 / 72%);
  border-radius: 999px;
  background: rgb(255 255 255 / 76%);
  box-shadow: 0 12px 34px rgb(15 23 42 / 6%);
}

.site-header nav a {
  border-radius: 999px;
  padding: 8px 13px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
}

.site-header nav a:hover {
  color: var(--text);
  background: var(--surface-alt);
}

.site-header .nav-button {
  color: #ffffff;
  background: var(--text);
}

.section {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 58px 0;
  scroll-margin-top: 92px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(440px, 1.1fr);
  align-items: center;
  gap: 48px;
  min-height: min(820px, calc(100vh - 68px));
  padding: 48px 0 76px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 750;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 680px;
  margin-bottom: 20px;
  font-size: clamp(44px, 5.6vw, 68px);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(30px, 3.7vw, 44px);
  line-height: 1.16;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 9px;
  font-size: 18px;
  line-height: 1.3;
}

p {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.hero-lede {
  max-width: 570px;
  font-size: 18px;
  line-height: 1.78;
}

.hero-actions {
  flex-wrap: wrap;
  gap: 12px;
  margin: 30px 0 18px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0 18px;
  font-size: 14px;
  font-weight: 750;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button.primary {
  border-color: var(--primary);
  color: #ffffff;
  background: var(--primary);
  box-shadow: 0 16px 34px rgb(37 99 235 / 24%);
}

.button.primary:hover {
  background: var(--primary-hover);
}

.button.secondary {
  background: rgb(255 255 255 / 82%);
}

.button.secondary:hover {
  border-color: #b9c4d4;
  background: #ffffff;
}

.button.full {
  width: 100%;
}

.trust-row {
  flex-wrap: wrap;
  gap: 8px;
}

.trust-row span {
  border: 1px solid rgb(216 222 232 / 80%);
  border-radius: 999px;
  padding: 7px 10px;
  color: #334155;
  background: rgb(255 255 255 / 74%);
  font-size: 12px;
  font-weight: 650;
}

.hero-art {
  position: relative;
}

.app-icon {
  position: absolute;
  top: -38px;
  left: 24px;
  z-index: 2;
  width: 108px;
  height: 108px;
  border-radius: 26px;
  box-shadow: 0 22px 54px rgb(15 23 42 / 18%);
}

.screenshot-frame {
  overflow: hidden;
  border: 1px solid rgb(216 222 232 / 82%);
  border-radius: 26px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero .screenshot-frame {
  transform: translateY(14px);
}

.section-heading {
  max-width: 680px;
}

.section-heading.centered {
  margin: 0 auto 30px;
  text-align: center;
}

.problem {
  padding-top: 28px;
}

.problem-grid,
.security-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.problem-grid article,
.security-grid article,
.steps article,
.download-card {
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 20px;
  background: rgb(255 255 255 / 78%);
  box-shadow: 0 16px 40px rgb(15 23 42 / 5%);
}

.problem-grid article,
.security-grid article {
  padding: 24px;
}

.problem-grid strong {
  display: block;
  margin-bottom: 8px;
  font-size: 17px;
}

.problem-grid p,
.security-grid p,
.steps p {
  margin-bottom: 0;
  font-size: 14px;
  line-height: 1.7;
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.demo-video {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  align-items: center;
  gap: 22px;
  margin: 0 0 22px;
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 26px;
  padding: 18px;
  background: rgb(255 255 255 / 78%);
  box-shadow: 0 18px 48px rgb(15 23 42 / 7%);
}

.demo-video video {
  width: 100%;
  overflow: hidden;
  border: 1px solid rgb(216 222 232 / 76%);
  border-radius: 18px;
  background: #ffffff;
}

.demo-video strong {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
}

.demo-video p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
}

.steps article {
  min-height: 176px;
  padding: 22px;
}

.steps span {
  display: inline-grid;
  width: 34px;
  height: 34px;
  margin-bottom: 20px;
  place-items: center;
  border-radius: 12px;
  color: var(--primary);
  background: #edf4ff;
  font-size: 12px;
  font-weight: 800;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  align-items: center;
  gap: 52px;
}

.split.reverse {
  grid-template-columns: minmax(320px, 0.86fr) minmax(0, 1.14fr);
}

.split-copy p {
  max-width: 580px;
}

.check-list {
  display: grid;
  gap: 10px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 24px;
  color: #334155;
  font-size: 14px;
  line-height: 1.7;
}

.check-list li::before {
  position: absolute;
  top: 9px;
  left: 0;
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: var(--success);
  content: "";
}

.security {
  border-block: 1px solid rgb(216 222 232 / 70%);
  padding-block: 64px;
}

.text-link {
  color: var(--primary);
  font-weight: 750;
}

.text-link:hover {
  color: var(--primary-hover);
}

.download {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 380px;
  align-items: center;
  gap: 42px;
}

.download-card {
  display: grid;
  gap: 10px;
  padding: 18px;
}

.wechat-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 104px;
  align-items: center;
  gap: 16px;
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 18px;
  padding: 14px;
  background: rgb(255 255 255 / 72%);
}

.wechat-card strong {
  display: block;
  margin-bottom: 6px;
  color: var(--text);
  font-size: 14px;
}

.wechat-card p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.wechat-card img {
  width: 104px;
  height: 104px;
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 16px;
  background: #fff;
}

code {
  overflow: auto;
  border-radius: 14px;
  padding: 13px;
  color: #e5e7eb;
  background: var(--code);
  font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
  font-size: 12px;
  line-height: 1.5;
}

.faq {
  max-width: 880px;
  padding-top: 48px;
}

.faq details {
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 18px;
  margin-bottom: 10px;
  padding: 18px 20px;
  background: rgb(255 255 255 / 78%);
}

.faq summary {
  cursor: pointer;
  font-size: 16px;
  font-weight: 750;
}

.faq details p {
  margin: 12px 0 0;
  font-size: 14px;
}

.site-footer {
  justify-content: center;
  gap: 18px;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  border-top: 1px solid rgb(216 222 232 / 82%);
  padding: 28px 0 40px;
  color: var(--muted);
  font-size: 13px;
}

.site-footer span {
  color: var(--text);
  font-weight: 750;
}

.site-footer a:hover {
  color: var(--primary);
}

.manual-page {
  background: #f7f8fb;
}

.manual-layout {
  display: grid;
  grid-template-columns: 216px minmax(0, 840px);
  gap: 36px;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 38px 0 76px;
}

.manual-toc {
  position: sticky;
  top: 86px;
  display: grid;
  align-self: start;
  gap: 4px;
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 20px;
  padding: 14px;
  background: rgb(255 255 255 / 78%);
  box-shadow: 0 16px 40px rgb(15 23 42 / 5%);
}

.manual-toc strong {
  margin-bottom: 6px;
  padding: 0 8px;
  font-size: 14px;
}

.manual-toc a {
  border-radius: 10px;
  padding: 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
}

.manual-toc a:hover {
  color: var(--text);
  background: var(--surface-alt);
}

.manual-content {
  min-width: 0;
}

.manual-hero,
.manual-section {
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 24px;
  margin-bottom: 16px;
  padding: 32px;
  background: rgb(255 255 255 / 82%);
  box-shadow: 0 16px 44px rgb(15 23 42 / 5%);
}

.manual-hero h1 {
  max-width: 760px;
  font-size: clamp(36px, 4.6vw, 54px);
  line-height: 1.12;
}

.manual-section h2 {
  font-size: clamp(24px, 3vw, 34px);
}

.manual-section ul,
.manual-section ol,
.manual-note ul {
  margin: 0;
  padding-left: 20px;
  color: #334155;
  line-height: 1.8;
}

.manual-section li {
  margin: 4px 0;
}

.manual-section figure {
  overflow: hidden;
  margin: 18px 0;
  border: 1px solid rgb(216 222 232 / 78%);
  border-radius: 22px;
  background: #ffffff;
  box-shadow: 0 18px 48px rgb(15 23 42 / 8%);
}

.manual-section figure img {
  width: 100%;
}

.manual-section figcaption {
  border-top: 1px solid #eef2f7;
  padding: 12px 14px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.manual-note {
  border: 1px solid #bfdbfe;
  border-radius: 18px;
  margin-top: 18px;
  padding: 16px;
  color: #334155;
  background: #eff6ff;
  font-size: 14px;
  line-height: 1.8;
}

.manual-section pre {
  overflow: auto;
  margin: 16px 0;
}

.manual-section pre code {
  display: block;
}

@media (max-width: 920px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-header nav {
    width: 100%;
    overflow-x: auto;
  }

  .hero,
  .split,
  .split.reverse,
  .download {
    grid-template-columns: 1fr;
  }

  .manual-layout {
    grid-template-columns: 1fr;
  }

  .manual-toc {
    position: static;
    grid-template-columns: repeat(2, 1fr);
  }

  .hero {
    min-height: 0;
  }

  .problem-grid,
  .security-grid,
  .steps {
    grid-template-columns: 1fr 1fr;
  }

  .demo-video {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .site-header,
  .section,
  .site-footer {
    width: min(100% - 28px, 1180px);
  }

  .section {
    padding: 46px 0;
  }

  h1 {
    font-size: 42px;
  }

  .problem-grid,
  .security-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .app-icon {
    width: 82px;
    height: 82px;
    border-radius: 20px;
  }

  .screenshot-frame {
    border-radius: 18px;
  }

  .manual-hero,
  .manual-section {
    border-radius: 18px;
    padding: 20px;
  }

  .manual-toc {
    grid-template-columns: 1fr;
  }
}

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