:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --text: #16202e;
  --text-2: #48566b;
  --muted: #7b8aa0;
  --border: #e2e7f0;
  --brand: #2b5cff;
  --brand-ink: #1b3fbd;
  --brand-soft: #eaefff;
  --shadow: 0 12px 40px rgba(22, 32, 46, 0.08);
  --max: 1040px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(900px 420px at 8% -10%, #e6ecff 0%, rgba(230, 236, 255, 0) 60%),
    radial-gradient(720px 380px at 100% 0%, #e4f5ee 0%, rgba(228, 245, 238, 0) 55%),
    var(--bg);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

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

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 2;
  background: rgba(244, 246, 251, 0.92);
  backdrop-filter: blur(12px);
}

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
  padding: 16px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 650;
  letter-spacing: 0.08em;
}

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

.top nav {
  display: flex;
  gap: 22px;
  color: var(--text-2);
  font-size: 15px;
}

.top nav a:hover { color: var(--brand-ink); }

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 12px 24px 72px;
}

.hero {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 36px;
  align-items: center;
  padding: 28px 0 64px;
}

.kicker {
  margin: 0 0 8px;
  color: var(--brand-ink);
  font-size: 14px;
  font-weight: 650;
  letter-spacing: 0.04em;
}

h1 {
  margin: 0;
  font-size: 64px;
  line-height: 1.05;
  letter-spacing: 0.12em;
  font-weight: 650;
}

.lead {
  margin: 18px 0 0;
  max-width: 38em;
  color: var(--text-2);
  font-size: 18px;
}

.dl-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.dl {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 196px;
  padding: 12px 16px;
  border-radius: 14px;
  background: var(--brand);
  color: #fff;
  box-shadow: 0 8px 20px rgba(43, 92, 255, 0.22);
}

.dl:hover { background: var(--brand-ink); }

.dl-mark {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
}

.dl-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.dl-text strong { font-size: 15px; font-weight: 650; }

.dl-text em {
  margin-top: 2px;
  font-style: normal;
  font-size: 12px;
  opacity: 0.85;
}

.soon {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.hero-mark {
  display: grid;
  place-items: center;
}

.hero-mark img {
  width: min(280px, 70vw);
  height: auto;
  filter: drop-shadow(0 18px 30px rgba(22, 48, 158, 0.18));
}

.features h2,
.download h2 {
  margin: 0;
  font-size: 28px;
  letter-spacing: 0.04em;
}

.section-note {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.cards li,
.platforms article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px 20px 18px;
  box-shadow: var(--shadow);
}

.cards h3,
.platforms h3 {
  margin: 0 0 6px;
  font-size: 17px;
}

.cards p,
.platforms p {
  margin: 0;
  color: var(--text-2);
}

.download { margin-top: 56px; }

.platforms {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 22px;
}

.platforms p { margin-bottom: 16px; font-size: 14px; }

.dl-block { min-width: 0; }

footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 28px 24px 40px;
  color: var(--muted);
  letter-spacing: 0.12em;
}

footer img {
  width: 28px;
  height: 28px;
}

.subpage {
  max-width: 640px;
  margin: 48px auto 80px;
  padding: 0 24px;
}

.subpage h1 {
  font-size: 36px;
  letter-spacing: 0.06em;
}

.subpage p { color: var(--text-2); }

.back {
  display: inline-block;
  margin-top: 8px;
  color: var(--brand-ink);
  font-weight: 650;
}

@media (max-width: 800px) {
  h1 { font-size: 48px; }
  .hero,
  .cards,
  .platforms { grid-template-columns: 1fr; }
  .hero-mark { order: -1; }
  .hero { padding-top: 8px; }
  .dl { flex: 1; }
}