:root {
  --ink: #073f3d;
  --text: #35555b;
  --muted: #668084;
  --green: #08725d;
  --mint: #e8f6f1;
  --blue: #2461f3;
  --blue-dark: #164bda;
  --orange: #ff7042;
  --purple: #8458ee;
  --cyan: #1aa9bd;
  --line: #dce9e7;
  --cloud: #f3f8f8;
  --section: #f7fbfb;
  --white: #fff;
  --shadow: 0 14px 36px rgba(8, 68, 63, .12);
  --radius: 18px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  color: var(--text);
  background: var(--white);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
  font-size: clamp(13px, 1.12vw, 16px);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { display: block; max-width: 100%; }
picture { display: block; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
button, input, select, textarea { font: inherit; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 {
  color: var(--ink);
  line-height: 1.18;
  letter-spacing: -.035em;
}
h1 { margin-bottom: 14px; font-size: clamp(36px, 4.25vw, 62px); }
h2 { margin-bottom: 8px; font-size: clamp(25px, 2.75vw, 40px); }
h3 { margin-bottom: 5px; font-size: clamp(15px, 1.35vw, 19px); }
p { margin-bottom: 0; }
.shell { width: min(1180px, calc(100% - clamp(36px, 8vw, 112px))); margin-inline: auto; }
.section { padding: clamp(34px, 4.5vw, 64px) 0; }
.section-heading { max-width: 830px; margin-bottom: clamp(18px, 2.5vw, 32px); }
.section-heading > p { font-size: clamp(13px, 1.18vw, 17px); }
.section-heading.compact { max-width: none; }
.narrow { max-width: 1080px; }

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  height: clamp(56px, 5.5vw, 72px);
  background: rgba(255, 255, 255, .96);
  border-bottom: 1px solid rgba(0, 72, 65, .08);
  backdrop-filter: blur(16px);
}
.nav-shell {
  width: min(1180px, calc(100% - clamp(32px, 8vw, 112px)));
  height: 100%;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand { display: block; width: clamp(120px, 13vw, 180px); flex: 0 0 auto; }
.brand img { width: 100%; height: auto; }
.site-nav { display: flex; align-items: center; gap: clamp(18px, 3.2vw, 44px); color: var(--ink); font-weight: 700; }
.site-nav a { position: relative; padding: 10px 0; white-space: nowrap; }
.site-nav a:not(.nav-download)::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 4px;
  height: 2px;
  background: var(--green);
  transition: right .18s ease;
}
.site-nav a:hover::after,
.site-nav a:focus-visible::after,
.site-nav a.active::after { right: 0; }
.site-nav .nav-download {
  padding: 9px clamp(18px, 2vw, 26px);
  color: var(--white);
  background: var(--blue);
  border-radius: 999px;
  box-shadow: 0 8px 20px rgba(36, 97, 243, .23);
}
.site-nav .nav-download:hover,
.site-nav .nav-download:focus-visible { background: var(--blue-dark); transform: translateY(-1px); }
.menu-toggle {
  display: none;
  width: 46px;
  height: 46px;
  padding: 2px;
  border: 0;
  background: transparent;
  border-radius: 10px;
  cursor: pointer;
}
.menu-toggle img { width: 100%; height: 100%; object-fit: cover; }
.mobile-download { display: none; }

.hero { position: relative; overflow: hidden; background: #f1f8f5; }
.home-hero .hero-grid {
  display: grid;
  grid-template-columns: minmax(0, .82fr) minmax(0, 1.18fr);
  align-items: stretch;
  min-height: clamp(300px, 36vw, 510px);
}
.hero-copy { position: relative; z-index: 2; align-self: center; padding: clamp(28px, 4vw, 58px) 0; }
.hero-copy > p:not(.breadcrumb) { max-width: 650px; font-size: clamp(13px, 1.22vw, 18px); line-height: 1.5; }
.button-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: clamp(20px, 2.5vw, 30px); }
.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px clamp(21px, 2.4vw, 34px);
  border: 2px solid transparent;
  border-radius: 999px;
  font-weight: 800;
  line-height: 1.15;
  transition: transform .18s ease, background-color .18s ease;
}
.button.primary { color: var(--white); background: var(--blue); box-shadow: 0 10px 24px rgba(36, 97, 243, .25); }
.button.primary:hover,
.button.primary:focus-visible { background: var(--blue-dark); transform: translateY(-2px); }
.button.secondary { color: var(--ink); background: rgba(255, 255, 255, .83); border-color: var(--ink); }
.button.secondary:hover,
.button.secondary:focus-visible { background: var(--white); transform: translateY(-2px); }
.button.large { min-width: 235px; min-height: 50px; font-size: clamp(15px, 1.35vw, 19px); }
.supporting { display: block; margin: 7px 0 0 18px; color: var(--muted); font-size: 12px; }
.hero-art { min-width: 0; align-self: stretch; }
.hero-art picture,
.hero-art img { width: 100%; height: 100%; }
.hero-art img { object-fit: cover; object-position: 56% center; }

.split-layout {
  display: grid;
  grid-template-columns: minmax(0, .95fr) minmax(0, 1.05fr);
  align-items: center;
  gap: clamp(28px, 5vw, 72px);
}
.overview-art { order: 2; overflow: hidden; border-radius: 0 0 0 44px; }
.overview-art picture { aspect-ratio: 441 / 173; }
.overview-art img { width: 100%; height: 100%; object-fit: cover; object-position: 63% center; }
.overview-copy { order: 1; }
.overview-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.icon-card { padding: 12px 8px; text-align: center; border-right: 1px solid var(--line); }
.icon-card:last-child { border-right: 0; }
.icon-card img,
.feature-card img,
.function-grid img,
.audience-grid img,
.highlight-grid img {
  width: 40px;
  height: 40px;
  margin: 0 auto 8px;
  border-radius: 50%;
  object-fit: cover;
}
.icon-card p,
.feature-card p,
.function-grid p,
.audience-grid p,
.highlight-grid p { font-size: clamp(11px, .95vw, 14px); line-height: 1.45; }

.features-section { background: var(--section); }
.feature-stage { display: grid; gap: 18px; }
.feature-grid { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 9px; }
.feature-card {
  min-width: 0;
  min-height: 168px;
  padding: 14px 9px;
  text-align: center;
  background: var(--white);
  border: 1px solid rgba(8, 114, 93, .09);
  border-radius: 16px;
}
.social-banner { overflow: hidden; border-radius: var(--radius); box-shadow: var(--shadow); }
.social-banner picture { aspect-ratio: 4 / 1; }
.social-banner img { width: 100%; height: 100%; object-fit: cover; object-position: center 42%; }

.games-visual { position: relative; overflow: hidden; border: 6px solid var(--white); border-radius: 16px; box-shadow: var(--shadow); }
.games-visual picture { aspect-ratio: 1080 / 170; }
.games-visual img { width: 100%; height: 100%; object-fit: cover; }
.game-labels { position: absolute; inset: 0; display: grid; grid-template-columns: repeat(6, 1fr); pointer-events: none; }
.game-labels span { align-self: start; min-height: 2.55em; padding: clamp(7px, .85vw, 11px); color: var(--white); font-size: clamp(11px, 1.1vw, 16px); font-weight: 800; line-height: 1.2; text-shadow: 0 2px 8px rgba(0, 0, 0, .24); }
.game-labels span:nth-child(1) { background: #e9793f; }
.game-labels span:nth-child(2) { background: #15937c; }
.game-labels span:nth-child(3) { background: #ed7045; }
.game-labels span:nth-child(4) { background: #695bc4; }
.game-labels span:nth-child(5) { background: #3883db; }
.game-labels span:nth-child(6) { background: #198fc5; }
.game-copy-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin-top: 18px; }
.game-copy-grid article { padding: 15px 17px; background: var(--cloud); border-left: 4px solid var(--green); border-radius: 12px; }
.game-copy-grid p { font-size: clamp(11px, .97vw, 14px); line-height: 1.48; }
.operation-banner {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(220px, .65fr);
  align-items: center;
  margin-top: 18px;
  overflow: hidden;
  background: var(--mint);
  border-radius: var(--radius);
}
.operation-banner picture { height: 100%; min-height: 190px; }
.operation-banner img { width: 100%; height: 100%; object-fit: cover; object-position: 62% 64%; }
.operation-banner div { padding: 24px; }

.function-section { background: #f2f9f7; }
.function-layout { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr); align-items: center; gap: clamp(24px, 4vw, 56px); }
.function-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 9px; }
.function-grid article { padding: 12px 10px; text-align: center; background: var(--white); border: 1px solid var(--line); border-radius: 13px; }
.growth-art,
.clarity-art { overflow: hidden; border: 6px solid rgba(255, 255, 255, .9); border-radius: 18px; box-shadow: var(--shadow); }
.growth-art picture { aspect-ratio: 373 / 152; }
.growth-art img { width: 100%; height: 100%; object-fit: cover; object-position: 58% center; }

.dual-section { background: var(--white); }
.dual-layout { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 18px; }
.player-panel,
.audience-panel { min-width: 0; }
.player-panel > h2,
.audience-panel > h2 { font-size: clamp(22px, 2.35vw, 34px); }
.player-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.player-grid article { min-height: 160px; padding: 18px; background: var(--cloud); border-radius: 15px; }
.player-grid article:first-child { border-left: 4px solid #20a77f; }
.player-grid article:last-child { border-left: 4px solid var(--blue); }
.player-grid p { font-size: clamp(11px, .96vw, 14px); line-height: 1.48; }
.audience-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 7px; }
.audience-grid article { min-width: 0; min-height: 160px; padding: 12px 7px; text-align: center; border-radius: 14px; }
.audience-grid article:nth-child(1) { background: #fff0e7; }
.audience-grid article:nth-child(2) { background: #e8f7f1; }
.audience-grid article:nth-child(3) { background: #eaf2ff; }
.audience-grid article:nth-child(4) { background: #f2ebff; }

.clarity-section { background: #f7fbfb; }
.clarity-layout { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); align-items: center; gap: clamp(24px, 4vw, 56px); }
.clarity-art picture { aspect-ratio: 456 / 104; }
.clarity-art img { width: 100%; height: 100%; object-fit: cover; object-position: 61% center; }

.final-cta { padding: clamp(30px, 3.8vw, 48px) 0; background: #e8f5f1; }
.cta-shell { display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.cta-shell h2 { font-size: clamp(24px, 2.65vw, 38px); }
.cta-shell > div:last-child { flex: 0 0 auto; text-align: center; }
.cta-shell .supporting { margin-left: 0; }
.site-footer { padding: clamp(32px, 4vw, 50px) 0; background: var(--white); border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1.25fr; gap: clamp(28px, 5vw, 64px); }
.footer-grid img { width: 145px; height: auto; margin-bottom: 8px; }
.footer-grid h2 { font-size: 16px; }
.footer-grid p,
.footer-grid a { display: block; margin-bottom: 4px; font-size: 13px; }

.download-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  display: none;
  background-color: rgba(246, 251, 248, .76);
  z-index: 0;
}
.download-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, .88fr) minmax(0, 1.12fr);
  align-items: stretch;
  min-height: clamp(350px, 42vw, 590px);
}
.download-hero .hero-copy { align-self: center; }
.download-hero h1 { font-size: clamp(34px, 3.75vw, 54px); }
.breadcrumb { margin-bottom: 12px; color: #527276; }
.breadcrumb a { text-decoration: underline; text-underline-offset: 4px; }
.app-inline { display: flex; align-items: center; gap: 14px; margin: 18px 0; }
.app-inline img { width: clamp(72px, 7.5vw, 100px); height: auto; border-radius: 16px; box-shadow: 0 8px 24px rgba(2, 69, 63, .12); }
.app-inline h2,
.app-inline h3 { margin-bottom: 4px; }
.app-inline p { line-height: 1.42; }
.back-link { display: block; width: max-content; margin-top: 13px; color: var(--blue); font-weight: 700; text-decoration: underline; text-underline-offset: 4px; }
.download-games { display: none; margin-top: 12px; }
.download-panel-section { background: #f3f9f7; }
.download-panel { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); overflow: hidden; background: var(--white); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.download-app-card,
.qr-card { padding: clamp(24px, 3vw, 38px); }
.download-app-card { border-right: 1px solid var(--line); }
.qr-card { display: grid; grid-template-columns: 132px minmax(0, 1fr); align-items: center; gap: 20px; }
.qr-card > img { width: 132px; height: 132px; object-fit: cover; border-radius: 14px; }
.download-url { overflow-wrap: anywhere; font-size: 13px; line-height: 1.45; }
.highlight-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; }
.highlight-grid article { min-width: 0; padding: 18px; background: var(--cloud); border-radius: 15px; }
.highlight-grid img { margin-left: 0; }
.download-highlight-art { margin-top: 18px; overflow: hidden; border-radius: var(--radius); box-shadow: var(--shadow); }
.download-highlight-art picture { aspect-ratio: 1080 / 170; }
.download-highlight-art img { width: 100%; height: 100%; object-fit: cover; }
.faq-section { background: #f7fbfb; }
.faq-list { display: grid; gap: 8px; }
.faq-list details { overflow: clip; background: #eef3f5; border-radius: 9px; }
.faq-list details[open] { background: var(--mint); }
.faq-list summary { min-height: 46px; padding: 11px 16px; color: var(--ink); font-weight: 800; cursor: pointer; }
.faq-list details p { padding: 0 16px 16px; }
.download-cta .back-link { margin-inline: auto; }

.error-page { min-height: 100vh; background: var(--white); }
.error-page main { background: #f1f8f5; }
.error-hero {
  position: relative;
  overflow: hidden;
  min-height: clamp(500px, 66vh, 760px);
  display: grid;
  align-items: center;
  background:
    radial-gradient(circle at 14% 22%, rgba(255, 206, 49, .22) 0 9%, transparent 9.4%),
    radial-gradient(circle at 90% 78%, rgba(36, 97, 243, .11) 0 14%, transparent 14.4%),
    linear-gradient(135deg, #f7fcfa 0%, #e7f5f0 100%);
}
.error-shell {
  display: grid;
  grid-template-columns: minmax(0, .72fr) minmax(0, 1.28fr);
  align-items: center;
  gap: clamp(30px, 5vw, 76px);
  padding-block: clamp(52px, 7vw, 92px);
}
.error-copy { position: relative; z-index: 2; }
.error-code {
  margin-bottom: -10px;
  color: var(--blue);
  font-size: clamp(92px, 13vw, 176px);
  font-weight: 900;
  line-height: .88;
  letter-spacing: -.08em;
  text-shadow: 0 14px 30px rgba(36, 97, 243, .14);
}
.error-copy h1 { margin-bottom: 12px; font-size: clamp(34px, 4vw, 58px); }
.error-copy > p:not(.error-code) { max-width: 520px; font-size: clamp(14px, 1.2vw, 18px); }
.error-art {
  overflow: hidden;
  padding: clamp(16px, 2.6vw, 34px);
  background: rgba(255, 255, 255, .7);
  border: 1px solid rgba(8, 114, 93, .11);
  border-radius: clamp(24px, 4vw, 48px);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}
.error-art picture { aspect-ratio: 526 / 268; }
.error-art img { width: 100%; height: 100%; object-fit: cover; }

a:focus-visible,
button:focus-visible,
summary:focus-visible { outline: 3px solid #ffce31; outline-offset: 3px; }

@media (max-width: 1000px) {
  .site-nav { gap: 18px; }
  .feature-card { min-height: 178px; }
  .audience-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 780px) {
  html { scroll-padding-top: 66px; }
  .site-header { height: 60px; }
  .nav-shell { width: calc(100% - 28px); }
  .brand { width: 142px; }
  .mobile-download {
    display: inline-flex;
    min-height: 42px;
    align-items: center;
    justify-content: center;
    margin-left: auto;
    padding: 8px 21px;
    color: var(--white);
    background: var(--blue);
    border-radius: 999px;
    font-weight: 800;
    box-shadow: 0 8px 20px rgba(36, 97, 243, .2);
  }
  .menu-toggle { display: block; }
  .site-nav {
    position: absolute;
    top: 60px;
    left: 12px;
    right: 12px;
    display: none;
    padding: 12px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 0 0 16px 16px;
    box-shadow: var(--shadow);
  }
  .site-nav.open { display: grid; gap: 2px; }
  .site-nav a { min-height: 44px; padding: 10px 14px; }
  .site-nav .nav-download { margin-top: 5px; text-align: center; }
  .site-nav a::after { display: none; }

  .home-hero .hero-grid { grid-template-columns: 1fr; }
  .hero-copy { padding: 26px 0 18px; }
  .home-hero .hero-art { height: clamp(245px, 42vw, 330px); margin-inline: calc(clamp(36px, 8vw, 112px) / -2); }
  .home-hero .hero-art img { object-position: 54% center; }
  .feature-stage { grid-template-columns: minmax(0, 1.3fr) minmax(0, .85fr); align-items: stretch; }
  .feature-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .social-banner picture { height: 100%; aspect-ratio: auto; }
  .social-banner img { object-position: 37% center; }
  .games-visual picture,
  .download-highlight-art picture { aspect-ratio: 730 / 252; }
  .game-labels { grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(2, 1fr); }
  .game-labels span { padding: 11px; font-size: 15px; }
  .game-copy-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .function-layout { grid-template-columns: minmax(0, 1.25fr) minmax(0, .75fr); }
  .function-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .dual-layout { grid-template-columns: 1fr; gap: 30px; }
  .audience-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }

  .download-hero {
    background-color: #f1f8f5;
    background-image: image-set(
      url("download-hero-art.avif") type("image/avif"),
      url("download-hero-art.webp") type("image/webp"),
      url("download-hero-art.png") type("image/png")
    );
    background-position: center;
    background-size: cover;
  }
  .download-hero::before { display: block; }
  .download-hero-grid { display: block; min-height: 0; }
  .download-hero .hero-copy { max-width: 660px; padding: 30px 0 34px; }
  .download-hero .hero-art { display: none; }
  .download-games { display: block; }
  .download-panel { grid-template-columns: 1fr 1fr; }
  .download-app-card,
  .qr-card { padding: 22px; }
  .qr-card { grid-template-columns: 106px minmax(0, 1fr); gap: 14px; }
  .qr-card > img { width: 106px; height: 106px; }
  .highlight-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .error-shell { grid-template-columns: 1fr; gap: 28px; padding-block: 42px; }
  .error-copy { text-align: center; }
  .error-copy > p:not(.error-code) { margin-inline: auto; }
  .error-copy .button-row { justify-content: center; }
  .error-art { width: min(650px, 100%); margin-inline: auto; }
}

@media (min-width: 781px) and (max-width: 900px) {
  .download-page { font-size: 14px; }
  .download-page .site-header { height: 60px; }
  .download-page .nav-shell { width: calc(100% - 28px); }
  .download-page .brand { width: 142px; }
  .download-page .mobile-download {
    display: inline-flex;
    min-height: 42px;
    align-items: center;
    justify-content: center;
    margin-left: auto;
    padding: 8px 21px;
    color: var(--white);
    background: var(--blue);
    border-radius: 999px;
    font-weight: 800;
    box-shadow: 0 8px 20px rgba(36, 97, 243, .2);
  }
  .download-page .menu-toggle { display: block; }
  .download-page .site-nav {
    position: absolute;
    top: 60px;
    left: 12px;
    right: 12px;
    display: none;
    padding: 12px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 0 0 16px 16px;
    box-shadow: var(--shadow);
  }
  .download-page .site-nav.open { display: grid; gap: 2px; }
  .download-page .site-nav a { min-height: 44px; padding: 10px 14px; }
  .download-page .site-nav .nav-download { margin-top: 5px; text-align: center; }
  .download-page .site-nav a::after { display: none; }
  .download-page .download-hero {
    background-color: #f1f8f5;
    background-image: image-set(
      url("download-hero-art.avif") type("image/avif"),
      url("download-hero-art.webp") type("image/webp"),
      url("download-hero-art.png") type("image/png")
    );
    background-position: center;
    background-size: cover;
  }
  .download-page .download-hero::before { display: block; }
  .download-page .download-hero-grid { display: block; min-height: 0; }
  .download-page .download-hero .hero-copy { max-width: 660px; padding: 30px 0 34px; }
  .download-page .download-hero .hero-art { display: none; }
  .download-page .download-hero .button.large { width: 100%; }
  .download-page .download-games { display: block; }
  .download-page .games-visual picture,
  .download-page .download-highlight-art picture { aspect-ratio: 730 / 252; }
  .download-page .game-labels { grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(2, 1fr); }
  .download-page .game-labels span { padding: 11px; font-size: 15px; }
  .download-page .download-panel { grid-template-columns: 1fr 1fr; }
  .download-page .download-app-card,
  .download-page .qr-card { padding: 22px; }
  .download-page .qr-card { grid-template-columns: 106px minmax(0, 1fr); gap: 14px; }
  .download-page .qr-card > img { width: 106px; height: 106px; }
  .download-page .highlight-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 600px) {
  body { font-size: 14px; }
  .shell { width: calc(100% - 28px); }
  .section { padding: 34px 0; }
  .brand { width: 132px; }
  .mobile-download { min-height: 40px; padding-inline: 17px; }
  .menu-toggle { width: 42px; height: 42px; }
  h1 { font-size: clamp(34px, 10vw, 46px); }
  h2 { font-size: clamp(24px, 7.3vw, 32px); }
  h3 { font-size: 16px; }

  .home-hero .hero-art { height: 250px; margin-inline: -14px; }
  .button-row { margin-top: 20px; }
  .button { flex: 1 1 145px; padding-inline: 16px; }
  .supporting { margin-left: 0; text-align: center; }
  .split-layout { grid-template-columns: 1fr; gap: 22px; }
  .overview-copy { order: 1; }
  .overview-art { order: 2; border-radius: 18px; }
  .overview-grid { gap: 5px; }
  .icon-card { padding: 10px 5px; }
  .icon-card img { width: 36px; height: 36px; }
  .icon-card h3 { font-size: 14px; }
  .icon-card p { font-size: 10px; }

  .feature-stage { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 7px; }
  .feature-card { min-height: 174px; padding: 12px 8px; }
  .feature-card p { font-size: 11px; }
  .social-banner picture { height: 240px; }
  .social-banner img { object-position: 36% center; }
  .game-labels span { padding: 8px; font-size: 12px; }
  .game-copy-grid { gap: 7px; }
  .game-copy-grid article { padding: 12px; }
  .operation-banner { grid-template-columns: 1fr; }
  .operation-banner picture { min-height: 205px; }
  .operation-banner div { padding: 18px; }

  .function-layout { grid-template-columns: 1fr; gap: 22px; }
  .function-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 7px; }
  .function-grid article { padding: 11px 8px; }
  .growth-art picture { aspect-ratio: 373 / 152; }
  .player-grid { grid-template-columns: 1fr; }
  .player-grid article { min-height: 0; }
  .audience-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .audience-grid article { min-height: 168px; padding: 13px 9px; }
  .clarity-layout { grid-template-columns: 1fr; gap: 20px; }
  .clarity-art picture { aspect-ratio: 456 / 104; }
  .cta-shell { display: grid; text-align: center; }
  .footer-grid { grid-template-columns: 1.4fr 1fr; gap: 24px; }
  .footer-grid > div:last-child { grid-column: 1 / -1; }

  .download-hero .hero-copy { padding: 26px 0 30px; }
  .download-hero .button.large { width: 100%; }
  .download-panel { grid-template-columns: 1fr; }
  .download-app-card { border-right: 0; border-bottom: 1px solid var(--line); }
  .qr-card { grid-template-columns: 104px minmax(0, 1fr); }
  .highlight-grid { gap: 8px; }
  .highlight-grid article { padding: 14px 12px; }
  .faq-list summary { min-height: 44px; }
}

@media (max-width: 390px) {
  .nav-shell { width: calc(100% - 20px); }
  .brand { width: 118px; }
  .mobile-download { padding-inline: 13px; }
  .game-copy-grid,
  .highlight-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-grid > div:last-child { grid-column: auto; }
  .qr-card { grid-template-columns: 88px minmax(0, 1fr); padding: 16px; }
  .qr-card > img { width: 88px; height: 88px; }
  .download-url { font-size: 11px; }
  .error-hero { min-height: 0; }
  .error-shell { padding-block: 34px 42px; }
  .error-code { font-size: clamp(82px, 29vw, 116px); }
  .error-art { padding: 12px; border-radius: 22px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}