:root {
  color-scheme: light;
  --paper: #ffffff;
  --surface: #f7fbff;
  --panel: #ffffff;
  --ink: #202124;
  --muted: #5f6368;
  --muted-strong: #3c4043;
  --line: #d7e4f7;
  --accent: #1a73e8;
  --accent-strong: #0b57d0;
  --accent-soft: #e8f0fe;
  --accent-ink: #ffffff;
  --shadow: 0 26px 70px rgba(26, 115, 232, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  padding: 0 clamp(24px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(18px);
}

.brand,
.top-nav,
.hero-actions,
.download-actions,
.footer-links {
  display: flex;
  align-items: center;
}

.brand {
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  font-size: 18px;
  font-weight: 800;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 10px;
}

.top-nav {
  gap: clamp(14px, 2vw, 26px);
  color: var(--muted);
  font-size: 14px;
  font-weight: 680;
}

.top-nav a {
  text-decoration: none;
  white-space: nowrap;
}

.top-nav a:hover {
  color: var(--accent-strong);
}

.nav-primary,
.button.primary {
  color: var(--accent-ink);
  background: var(--accent);
}

.nav-primary {
  padding: 10px 16px;
  border-radius: 999px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(360px, 0.88fr) minmax(0, 1.12fr);
  gap: clamp(38px, 6vw, 82px);
  align-items: center;
  min-height: min(780px, calc(100dvh - 72px));
  padding: clamp(56px, 7vw, 94px) clamp(24px, 5vw, 72px);
  background: linear-gradient(180deg, #ffffff 0%, #f7fbff 64%, #ffffff 100%);
}

.hero-copy {
  max-width: 620px;
}

.status-line {
  display: inline-flex;
  margin: 0 0 18px;
  padding: 8px 14px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 13px;
  font-weight: 760;
}

h1,
h2,
h3,
p {
  letter-spacing: 0;
}

h1 {
  max-width: 11ch;
  margin: 0;
  color: var(--ink);
  font-size: clamp(44px, 4.6vw, 66px);
  line-height: 1.02;
}

.hero-subtitle {
  max-width: 640px;
  margin: 24px 0 0;
  color: var(--muted-strong);
  font-size: clamp(18px, 1.8vw, 22px);
  line-height: 1.56;
}

.hero-actions,
.download-actions {
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid var(--line);
  border-radius: 999px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 760;
  white-space: nowrap;
}

.button.primary {
  border-color: var(--accent);
  box-shadow: 0 12px 28px rgba(26, 115, 232, 0.22);
}

.button.secondary {
  color: var(--accent-strong);
  background: #ffffff;
}

.hero-card {
  overflow: hidden;
  border: 1px solid #c8dcfb;
  border-radius: 28px;
  background: #ffffff;
  box-shadow: var(--shadow);
}

.hero-card img {
  display: block;
  width: 100%;
  min-height: 360px;
  object-fit: cover;
  object-position: top center;
  background: var(--surface);
}

.proof-strip,
.use-cases,
.privacy,
.download,
.changelog,
.faq {
  width: min(1180px, calc(100% - 40px));
  margin: clamp(54px, 7vw, 96px) auto 0;
}

.section-copy {
  max-width: 780px;
}

.section-copy h2,
.download h2,
.privacy h2,
.changelog h2,
.faq h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(34px, 4vw, 54px);
  line-height: 1.08;
}

.section-copy p,
.download p,
.privacy p,
.changelog p,
.faq p,
.card p {
  color: var(--muted);
  line-height: 1.66;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin-top: 28px;
}

.card {
  min-height: 168px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--panel);
  box-shadow: 0 12px 28px rgba(60, 64, 67, 0.07);
}

.card h3 {
  margin: 0 0 12px;
  font-size: 20px;
}

.feature-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.82fr) minmax(0, 1.18fr);
  gap: clamp(34px, 6vw, 72px);
  align-items: start;
}

.feature-list {
  display: grid;
  gap: 14px;
}

.feature-list article,
.privacy-list article,
.timeline article {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: #ffffff;
}

.feature-list h3,
.privacy-list h3,
.timeline h3 {
  margin: 0 0 10px;
}

.privacy-list,
.timeline {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 28px;
}

.download {
  display: grid;
  grid-template-columns: minmax(280px, 1fr) auto;
  gap: 24px;
  align-items: center;
  padding: 36px;
  border: 1px solid #c8dcfb;
  border-radius: 28px;
  background: #e8f0fe;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 14px;
  margin-top: clamp(70px, 8vw, 110px);
  padding: 30px clamp(24px, 5vw, 72px);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.footer-links {
  gap: 18px;
}

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

@media (max-width: 980px) {
  .hero,
  .feature-layout,
  .download {
    grid-template-columns: 1fr;
  }

  .card-grid,
  .privacy-list,
  .timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .site-header {
    min-height: auto;
    align-items: flex-start;
    flex-direction: column;
    padding: 18px 20px;
  }

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

  .hero {
    padding: 42px 20px;
  }

  h1 {
    font-size: clamp(40px, 12vw, 56px);
  }

  .card-grid,
  .privacy-list,
  .timeline {
    grid-template-columns: 1fr;
  }

  .hero-card img {
    min-height: 280px;
  }

  .download,
  .card,
  .feature-list article,
  .privacy-list article,
  .timeline article {
    padding: 20px;
    border-radius: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}