:root {
  --bg: #ffffff;
  --surface: #f5f7fa;
  --surface-strong: #eef3f4;
  --ink: #111827;
  --muted: #5b6472;
  --line: #d9e1e7;
  --accent: #0f8f87;
  --accent-dark: #0a6f69;
  --accent-soft: #e4f6f3;
  --blue: #2563eb;
  --shadow: 0 20px 60px rgba(17, 24, 39, .12);
  --radius: 8px;
  --max: 1160px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: Inter, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.65;
}

body.modal-open {
  overflow: hidden;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 72px;
  padding: 14px max(24px, calc((100vw - var(--max)) / 2));
  border-bottom: 1px solid rgba(217, 225, 231, .82);
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand img {
  width: 36px;
  height: 36px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.site-nav a {
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--ink);
  background: var(--surface);
}

.nav-toggle {
  display: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font: inherit;
  font-size: 15px;
  font-weight: 800;
  line-height: 1;
  cursor: pointer;
  transition: transform .18s ease, background .18s ease, border-color .18s ease;
}

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

.btn-primary {
  color: #fff;
  background: var(--accent);
}

.btn-primary:hover {
  background: var(--accent-dark);
}

.btn-ghost {
  color: var(--ink);
  border-color: var(--line);
  background: #fff;
}

.btn-secondary {
  color: var(--accent-dark);
  border-color: #b8d9d4;
  background: var(--accent-soft);
}

.btn-light {
  color: var(--accent-dark);
  background: #fff;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, .92fr) minmax(420px, 1.08fr);
  gap: 44px;
  align-items: center;
  max-width: var(--max);
  min-height: calc(100vh - 72px);
  margin: 0 auto;
  padding: 70px 24px 58px;
}

.hero h1,
.page-hero h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(40px, 6vw, 70px);
  line-height: 1.02;
  letter-spacing: 0;
}

.hero p,
.page-hero p {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

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

.hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 34px 0 0;
}

.hero-facts div {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.hero-facts dt {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.hero-facts dd {
  margin: 4px 0 0;
  font-size: 15px;
  font-weight: 800;
}

.hero-media {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.hero-media img,
.soft-image {
  width: 100%;
  border-radius: 6px;
  border: 1px solid var(--line);
}

.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 76px 24px;
}

.section-head {
  max-width: 720px;
  margin-bottom: 30px;
}

.section-head h2,
.split h2,
.download-band h2,
.note-panel h2,
.qr-section h2 {
  margin: 0;
  font-size: clamp(28px, 3.4vw, 42px);
  line-height: 1.12;
  letter-spacing: 0;
}

.section-head p,
.split p,
.download-band p,
.note-panel p,
.qr-section p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.platform-strip,
.feature-matrix,
.use-cases,
.download-options,
.faq-list {
  border-top: 1px solid var(--line);
}

.platforms,
.review-grid,
.feature-matrix,
.use-cases,
.download-options,
.faq-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.platforms article,
.review-grid figure,
.feature-matrix article,
.use-cases article,
.download-options article,
.faq-list article,
.scene-list article {
  margin: 0;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.icon-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 8px;
  color: var(--accent-dark);
  background: var(--accent-soft);
  font-size: 13px;
  font-weight: 900;
}

h2, h3 {
  letter-spacing: 0;
}

article h2,
article h3,
figure h3 {
  margin: 14px 0 8px;
  font-size: 21px;
  line-height: 1.25;
}

article p,
figure p,
blockquote {
  margin: 0;
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, .78fr) minmax(0, 1fr);
  gap: 34px;
  align-items: center;
}

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

.text-link {
  display: inline-flex;
  margin-top: 18px;
  color: var(--accent-dark);
  font-weight: 900;
}

.reviews {
  max-width: none;
  background: var(--surface);
}

.reviews > * {
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
}

.reviews .section-head {
  padding-left: 24px;
  padding-right: 24px;
}

.reviews .review-grid {
  padding-left: 24px;
  padding-right: 24px;
}

.review-grid figure {
  background: #fff;
}

blockquote {
  font-size: 17px;
  line-height: 1.75;
}

figcaption {
  margin-top: 16px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 900;
}

.download-band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 24px;
  margin-bottom: 70px;
  padding: 36px;
  border-radius: var(--radius);
  color: #fff;
  background: linear-gradient(135deg, #0d6f69, #123b52);
}

.download-band p,
.download-band h2 {
  color: #fff;
}

.page-hero {
  max-width: var(--max);
  margin: 0 auto;
  padding: 84px 24px 52px;
}

.download-hero {
  border-bottom: 1px solid var(--line);
}

.feature-matrix,
.use-cases,
.download-options,
.faq-list {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.feature-matrix article,
.use-cases article,
.download-options article,
.faq-list article {
  background: #fff;
}

.use-cases article span {
  color: var(--accent);
  font-size: 15px;
  font-weight: 900;
}

.download-options article {
  display: grid;
  gap: 14px;
  align-content: start;
}

.version-history {
  border-top: 1px solid var(--line);
}

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

.version-list article {
  display: grid;
  grid-template-columns: minmax(160px, .32fr) minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.version-list h3 {
  margin: 0;
  font-size: 22px;
  line-height: 1.2;
}

.version-list time {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

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

.version-list a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid #b8d9d4;
  border-radius: 8px;
  color: var(--accent-dark);
  background: var(--accent-soft);
  font-size: 14px;
  font-weight: 900;
  white-space: nowrap;
}

code {
  display: block;
  overflow-x: auto;
  padding: 14px;
  border: 1px solid #c8d4dc;
  border-radius: 8px;
  color: #d7fff6;
  background: #101820;
  font-family: "Cascadia Code", Consolas, Monaco, monospace;
  font-size: 14px;
  line-height: 1.6;
}

.qr-section {
  display: grid;
  grid-template-columns: minmax(0, .75fr) minmax(320px, 1fr);
  gap: 30px;
  align-items: center;
}

.note-panel {
  padding-top: 34px;
  padding-bottom: 34px;
  border: 1px solid #f0d3a2;
  border-radius: var(--radius);
  background: #fff8eb;
}

.faq-list article h2 {
  margin-top: 0;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 34px max(64px, calc((100vw - var(--max)) / 2));
  border-top: 1px solid var(--line);
  background: #101820;
  color: #fff;
}

.site-footer p {
  margin: 6px 0 0;
  color: #cbd5e1;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
  color: #d7fff6;
  font-weight: 800;
}

.download-modal[hidden] {
  display: none;
}

.download-modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 24px;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(16, 24, 32, .68);
}

.modal-card {
  position: relative;
  width: min(620px, 100%);
  padding: 30px;
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.modal-card h2 {
  margin: 0;
  font-size: 30px;
  line-height: 1.15;
}

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

.modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 22px;
}

.qr-grid div {
  display: grid;
  gap: 10px;
  justify-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 900;
  text-align: center;
}

.qr-grid img {
  width: 168px;
  border: 10px solid #fff;
  border-radius: 6px;
}

.qr-grid.inline {
  margin-top: 0;
}

.modal-link {
  display: inline-flex;
  margin-top: 18px;
  color: var(--accent-dark);
  font-weight: 900;
}

@media (max-width: 900px) {
  .site-header {
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
    padding: 8px 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    color: var(--ink);
    font-weight: 900;
  }

  .site-nav {
    display: none;
    order: 3;
    width: 100%;
    margin-left: 0;
    padding-top: 8px;
  }

  .site-nav.is-open {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .header-download {
    display: none;
  }

  .hero,
  .split,
  .qr-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 52px;
  }

  .hero-facts,
  .platforms,
  .review-grid,
  .feature-matrix,
  .use-cases,
  .download-options,
  .faq-list {
    grid-template-columns: 1fr;
  }

  .version-list article {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .download-band,
  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 560px) {
  .site-header {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero,
  .section,
  .page-hero {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero h1,
  .page-hero h1 {
    font-size: 38px;
  }

  .hero p,
  .page-hero p {
    font-size: 16px;
  }

  .hero-actions,
  .qr-grid {
    grid-template-columns: 1fr;
  }

  .btn {
    width: 100%;
  }

  .qr-grid {
    display: grid;
  }

  .modal-card {
    padding: 24px 18px;
  }

  .site-nav.is-open {
    grid-template-columns: 1fr;
  }
}