:root {
  color-scheme: light;
  --blue: #1268f7;
  --blue-strong: #075be9;
  --ink: #111827;
  --muted: #9298a4;
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }

html { background: #f5f7fb; }

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

.download-shell {
  width: min(100%, 820px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 42px 42px 158px;
  background: #fff;
}

.app-summary {
  display: grid;
  grid-template-columns: 156px minmax(0, 1fr);
  gap: 30px;
  align-items: center;
}

.app-icon {
  width: 156px;
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 1px solid #e8ebf0;
  border-radius: 30px;
  background: #fff;
  box-shadow: 0 10px 32px rgba(23, 43, 77, 0.04);
}

.app-icon span {
  position: relative;
  color: #101827;
  font-family: Arial, sans-serif;
  font-size: 54px;
  font-weight: 700;
  letter-spacing: -5px;
  line-height: 1;
}

.app-icon span::first-letter { color: var(--blue); }

.app-icon span::after {
  content: "";
  position: absolute;
  right: 3px;
  bottom: -13px;
  width: 45px;
  height: 7px;
  border-radius: 100%;
  background: #64d9ef;
  transform: rotate(-5deg);
}

.app-summary h1 {
  max-width: 510px;
  margin: 0 0 6px;
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 700;
  line-height: 1.24;
  letter-spacing: -0.025em;
}

.app-meta {
  display: flex;
  gap: 9px;
  align-items: center;
  margin: 0 0 7px;
  color: var(--muted);
  font-size: 23px;
}

.preview-section { margin-top: 50px; }

.screenshot-track {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 48px;
}

.screenshot-track figure {
  min-width: 0;
  margin: 0;
  overflow: hidden;
  border-radius: 2px;
  background: #f4f8ff;
  box-shadow: 0 10px 32px rgba(26, 65, 124, 0.06);
}

.screenshot-track img {
  display: block;
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top center;
}

.details-section { margin-top: 34px; }

.details-section h2 {
  margin: 0 0 18px;
  font-size: 30px;
  line-height: 1.3;
}

.detail-list {
  display: grid;
  gap: 11px;
  margin: 0;
  color: var(--muted);
  font-size: 23px;
}

.detail-list div {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 18px;
}

.detail-list dt,
.detail-list dd { margin: 0; }

.detail-list a { color: var(--blue); }

.detail-list a:hover,
.detail-list a:focus-visible {
  color: var(--blue-strong);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.download-notice {
  margin: 32px 0 0;
  color: #a2a7b0;
  font-size: 14px;
  text-align: center;
}

.install-dock {
  position: fixed;
  z-index: 20;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 18px max(28px, env(safe-area-inset-right)) calc(18px + env(safe-area-inset-bottom)) max(28px, env(safe-area-inset-left));
  background: rgba(255, 255, 255, 0.96);
  border-top: 1px solid rgba(235, 239, 245, 0.86);
  box-shadow: 0 -14px 34px rgba(22, 54, 102, 0.05);
  backdrop-filter: blur(14px);
}

.install-actions {
  width: min(100%, 736px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0 auto;
}

.install-button {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(135deg, #5c80ff 0%, #4770f8 100%);
  font-size: 26px;
  font-weight: 600;
  box-shadow: 0 12px 28px rgba(55, 100, 241, 0.18);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.install-button--tablet {
  background: linear-gradient(135deg, #13a5d8 0%, #137be3 100%);
}

.install-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 15px 34px rgba(55, 100, 241, 0.25);
}

.install-button:focus-visible {
  outline: 3px solid rgba(18, 104, 247, 0.28);
  outline-offset: 4px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 680px) {
  .download-shell { padding: 24px 20px 132px; }

  .app-summary {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 18px;
  }

  .app-icon { width: 104px; border-radius: 23px; }

  .app-icon span { font-size: 38px; letter-spacing: -4px; }

  .app-icon span::after {
    right: 2px;
    bottom: -10px;
    width: 31px;
    height: 5px;
  }

  .app-summary h1 {
    margin-bottom: 4px;
    font-size: clamp(19px, 5.5vw, 25px);
    line-height: 1.28;
  }

  .app-meta { gap: 6px; margin-bottom: 4px; font-size: 14px; }
  .preview-section { margin-top: 32px; }
  .screenshot-track { gap: 14px; }
  .screenshot-track figure { border-radius: 1px; }
  .details-section { margin-top: 28px; }
  .details-section h2 { margin-bottom: 15px; font-size: 24px; }
  .detail-list { gap: 10px; font-size: 16px; }

  .detail-list div {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 14px;
  }

  .download-notice { margin-top: 26px; font-size: 12px; }
  .install-dock { padding: 12px 20px calc(12px + env(safe-area-inset-bottom)); }
  .install-actions { gap: 10px; }
  .install-button { min-height: 56px; font-size: 18px; }
}

@media (max-width: 380px) {
  .download-shell { padding-right: 16px; padding-left: 16px; }
  .app-summary { grid-template-columns: 88px minmax(0, 1fr); gap: 14px; }
  .app-icon { width: 88px; border-radius: 20px; }
  .app-icon span { font-size: 32px; }
  .screenshot-track { gap: 10px; }
}