:root {
  color-scheme: dark;
  --bg: #101016;
  --panel: rgba(28, 28, 36, 0.86);
  --panel-strong: rgba(35, 35, 45, 0.96);
  --line: rgba(255, 255, 255, 0.10);
  --text: #f7f4ed;
  --muted: #b6b0a8;
  --gold: #ffd45a;
  --red: #ff3b3f;
  --ink: #050506;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  font-family: "Avenir Next", "PingFang SC", "Hiragino Sans GB", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 8%, rgba(255, 59, 63, 0.22), transparent 28rem),
    radial-gradient(circle at 82% 4%, rgba(255, 212, 90, 0.20), transparent 24rem),
    linear-gradient(145deg, #0b0b10 0%, #171720 52%, #101016 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.32;
  background-image:
    linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(to bottom, black, transparent 82%);
}

.page-shell {
  width: min(760px, calc(100% - 28px));
  margin: 0 auto;
  padding: 34px 0 48px;
}

.hero-card,
.guide-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--panel);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.42);
  backdrop-filter: blur(18px);
}

.hero-card {
  padding: 28px;
  min-height: 620px;
}

.hero-card::after {
  content: "";
  position: absolute;
  inset: auto 24px 24px auto;
  width: 140px;
  height: 8px;
  border-radius: 99px;
  background: linear-gradient(90deg, var(--red), var(--gold));
  opacity: 0.92;
}

.halo {
  position: absolute;
  border-radius: 999px;
  filter: blur(4px);
  pointer-events: none;
}

.halo-a {
  width: 280px;
  height: 280px;
  right: -120px;
  top: -90px;
  background: rgba(255, 212, 90, 0.16);
}

.halo-b {
  width: 220px;
  height: 220px;
  left: -96px;
  bottom: 80px;
  background: rgba(255, 59, 63, 0.14);
}

.brand-row {
  position: relative;
  display: flex;
  align-items: center;
  gap: 18px;
}

.app-logo {
  width: 92px;
  height: 92px;
  border-radius: 24px;
  object-fit: cover;
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.36);
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--gold);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.16em;
}

h1 {
  margin: 0;
  font-size: clamp(34px, 8vw, 58px);
  line-height: 0.98;
  letter-spacing: -0.06em;
}

.lead {
  position: relative;
  max-width: 560px;
  margin: 38px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.75;
}

.download-panel {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: stretch;
  margin-top: 34px;
}

.download-button,
.copy-button,
.text-link {
  border: 0;
  border-radius: 999px;
  text-decoration: none;
  cursor: pointer;
}

.download-button {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 72px;
  padding: 12px 22px;
  color: white;
  background: linear-gradient(135deg, #ff3439, #ff5145 58%, #ffbd4d);
  box-shadow: 0 18px 40px rgba(255, 59, 63, 0.26);
  transition: transform 160ms ease, filter 160ms ease;
}

.download-button:hover {
  transform: translateY(-2px);
  filter: saturate(1.08);
}

.download-icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 15px;
  color: var(--red);
  background: white;
  font-size: 30px;
  font-weight: 900;
  line-height: 1;
}

.download-button strong,
.download-button small {
  display: block;
}

.download-button strong {
  font-size: 18px;
}

.download-button small {
  margin-top: 3px;
  color: rgba(255, 255, 255, 0.80);
}

.copy-button {
  padding: 0 18px;
  color: var(--gold);
  background: var(--ink);
  font: inherit;
  font-weight: 800;
}

.meta-grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-top: 24px;
}

.meta-grid div,
.checksum,
.guide-card {
  background: var(--panel-strong);
}

.meta-grid div {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 18px;
}

.meta-grid span,
.checksum summary {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.meta-grid strong {
  display: block;
  margin-top: 5px;
  font-size: 14px;
}

.checksum {
  position: relative;
  margin-top: 12px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 18px;
}

.checksum code {
  display: block;
  margin-top: 10px;
  overflow-wrap: anywhere;
  color: var(--gold);
  font-size: 12px;
}

.guide-card {
  margin-top: 14px;
  padding: 22px;
}

.guide-card h2 {
  margin: 0 0 14px;
  color: var(--gold);
  font-size: 21px;
}

.guide-card ol {
  margin: 0;
  padding-left: 22px;
  color: var(--muted);
  line-height: 1.8;
}

.guide-card p {
  margin: 0 0 14px;
  color: var(--muted);
  line-height: 1.7;
}

.text-link {
  display: inline-flex;
  color: var(--gold);
  font-weight: 800;
}

@media (max-width: 620px) {
  .page-shell {
    width: min(100% - 22px, 760px);
    padding-top: 18px;
  }

  .hero-card {
    padding: 20px;
    min-height: 0;
  }

  .app-logo {
    width: 74px;
    height: 74px;
    border-radius: 20px;
  }

  .lead {
    margin-top: 28px;
    font-size: 16px;
  }

  .download-panel,
  .meta-grid {
    grid-template-columns: 1fr;
  }

  .copy-button {
    min-height: 48px;
  }
}