:root {
  color-scheme: dark;
  --bg: #07111c;
  --bg-deep: #040a12;
  --panel: #0c1a28;
  --panel-soft: #102437;
  --line: #234057;
  --text: #f4f8fb;
  --muted: #a6b7c7;
  --subtle: #6f8495;
  --blue: #3f8dff;
  --cyan: #56d6e8;
  --amber: #f0b84a;
  --shadow: rgba(0, 0, 0, 0.28);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg-deep);
  font-family: Inter, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  letter-spacing: 0;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 44px;
  background: rgba(4, 10, 18, 0.86);
  border-bottom: 1px solid rgba(86, 214, 232, 0.14);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 700;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: #03111d;
  background: var(--cyan);
  border-radius: 8px;
  font-size: 17px;
  font-weight: 800;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  color: var(--muted);
  font-size: 14px;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--text);
}

.hero {
  min-height: 590px;
  display: grid;
  grid-template-columns: minmax(360px, 0.86fr) minmax(520px, 1.14fr);
  gap: 54px;
  align-items: center;
  padding: 78px 56px 64px;
  background:
    linear-gradient(130deg, rgba(7, 17, 28, 0.98) 0%, rgba(8, 24, 38, 0.96) 48%, rgba(3, 10, 18, 1) 100%);
}

.hero-copy {
  max-width: 610px;
}

.hero h1 {
  margin: 0;
  font-size: 70px;
  line-height: 0.98;
  font-weight: 800;
}

.hero-lede {
  margin: 22px 0 0;
  color: #dbefff;
  font-size: 28px;
  line-height: 1.25;
  font-weight: 700;
}

.hero-text {
  margin: 22px 0 0;
  max-width: 560px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.hero-actions {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 0 18px;
  border-radius: 7px;
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.button svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

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

.button-primary {
  color: #05121f;
  background: linear-gradient(180deg, #72dcf0 0%, #3f8dff 100%);
  box-shadow: 0 16px 32px rgba(63, 141, 255, 0.24);
}

.button-secondary {
  color: var(--text);
  border: 1px solid var(--line);
  background: rgba(16, 36, 55, 0.76);
}

.product-frame {
  margin: 0;
}

.product-frame img {
  width: 100%;
  display: block;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  object-position: center;
  border: 1px solid rgba(86, 214, 232, 0.22);
  border-radius: 8px;
  box-shadow: 0 28px 70px var(--shadow);
}

.product-frame figcaption {
  margin-top: 12px;
  color: var(--subtle);
  font-size: 12px;
  line-height: 1.6;
}

.section {
  padding: 76px 56px;
}

.section-dark {
  background: var(--bg);
}

.section-light {
  color: #102033;
  background: #f6f9fc;
}

.section-heading {
  max-width: 760px;
}

.section h2 {
  margin: 0;
  font-size: 34px;
  line-height: 1.22;
}

.section-heading p,
.split-section p,
.download-panel p {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
}

.section-light h2,
.section-light p {
  color: #102033;
}

.feature-grid {
  margin-top: 34px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  min-height: 188px;
  padding: 26px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.feature-card h3 {
  margin: 0;
  font-size: 20px;
  line-height: 1.35;
}

.feature-card p {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(320px, 0.88fr) minmax(360px, 1.12fr);
  gap: 48px;
  align-items: start;
  background: #091622;
}

.privacy-list {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
  list-style: none;
}

.privacy-list li {
  padding: 18px 20px;
  color: #dceaf5;
  background: var(--panel-soft);
  border-left: 3px solid var(--cyan);
  border-radius: 7px;
  font-size: 15px;
}

.download-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  background: linear-gradient(90deg, #0b2034 0%, #0f2a3a 55%, #152315 100%);
  border-top: 1px solid rgba(240, 184, 74, 0.18);
  border-bottom: 1px solid rgba(240, 184, 74, 0.18);
}

.download-panel p {
  max-width: 720px;
}

.steps {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.steps article {
  min-height: 148px;
  padding: 22px;
  background: #ffffff;
  border: 1px solid #d9e3ec;
  border-radius: 8px;
}

.steps strong {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  color: #052034;
  background: var(--amber);
  border-radius: 8px;
}

.steps p {
  margin: 16px 0 0;
  color: #33475c;
  font-size: 14px;
  line-height: 1.75;
}

.site-footer {
  min-height: 88px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 56px;
  color: var(--subtle);
  background: var(--bg-deep);
  border-top: 1px solid rgba(86, 214, 232, 0.12);
  font-size: 13px;
}

.not-found {
  min-height: 100vh;
  display: grid;
  align-content: center;
  gap: 34px;
  padding: 44px;
  background: var(--bg-deep);
}

.not-found section {
  max-width: 560px;
}

.not-found h1 {
  margin: 0;
  font-size: 44px;
  line-height: 1.1;
}

.not-found p {
  margin: 18px 0 26px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

@media (max-width: 980px) {
  .site-header {
    padding: 0 24px;
  }

  .site-nav {
    gap: 18px;
  }

  .hero {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 34px;
    padding: 58px 24px 44px;
  }

  .hero h1 {
    font-size: 52px;
  }

  .hero-lede {
    font-size: 23px;
  }

  .section {
    padding: 56px 24px;
  }

  .feature-grid,
  .split-section,
  .steps {
    grid-template-columns: 1fr;
  }

  .download-panel {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 620px) {
  .site-header {
    height: auto;
    min-height: 68px;
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    gap: 12px;
    padding-top: 14px;
    padding-bottom: 14px;
  }

  .site-nav {
    width: 100%;
    justify-content: space-between;
  }

  .hero-actions {
    flex-direction: column;
    margin-top: 24px;
  }

  .button {
    width: 100%;
  }

  .hero h1 {
    font-size: 44px;
  }

  .hero-lede {
    font-size: 21px;
  }

  .hero-text {
    font-size: 15px;
  }

  .product-frame figcaption {
    margin-top: 8px;
    font-size: 11px;
  }

  .section h2 {
    font-size: 27px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    padding: 24px;
  }

  .not-found {
    padding: 28px 24px;
  }

  .not-found h1 {
    font-size: 34px;
  }
}

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

  .button {
    transition: none;
  }
}