:root {
  --brand: #433dff;
  --accent: #e8590c;
  --text: #1f2328;
  --muted: #59636e;
  --line: #e3e6ea;
  --bg-alt: #f6f7fb;
  --radius: 12px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  color: var(--text);
  line-height: 1.7;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body { margin: 0; background: #fff; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.ak { color: var(--brand); }

/* 顶栏 */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand { font-size: 22px; font-weight: 700; color: var(--text); }
.brand:hover { text-decoration: none; }
.nav nav { display: flex; gap: 24px; }
.nav nav a { color: var(--text); font-size: 15px; }
.nav nav a.hl { color: var(--accent); font-weight: 600; }

/* 首屏 */
.hero {
  padding: 88px 0 72px;
  text-align: center;
  background: linear-gradient(180deg, #eef1ff 0%, #fff 100%);
}
.hero h1 { margin: 0; font-size: 56px; line-height: 1.2; letter-spacing: 1px; }
.hero .lead { margin: 16px 0 4px; font-size: 22px; font-weight: 600; }
.hero .sub { margin: 0; color: var(--muted); }
.flow {
  list-style: none; padding: 0; margin: 40px auto 0;
  display: flex; justify-content: center; align-items: stretch; gap: 40px;
}
.flow li { position: relative; }
.flow li + li::before {
  content: "→"; position: absolute; left: -30px; top: 50%;
  transform: translateY(-50%); color: var(--muted); font-size: 20px;
}
.flow a {
  display: block; min-width: 180px; padding: 14px 20px;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  color: var(--text);
}
.flow a:hover { border-color: var(--brand); text-decoration: none; }
.flow b { display: block; font-size: 18px; color: var(--brand); }
.flow span { font-size: 14px; color: var(--muted); }

/* 区块 */
.section { padding: 72px 0; }
.section.alt { background: var(--bg-alt); }
.section h2 { margin: 0 0 32px; font-size: 28px; text-align: center; }
.grid { display: grid; gap: 24px; }
.cards { grid-template-columns: repeat(2, 1fr); }
.two { grid-template-columns: repeat(2, 1fr); }
.three { grid-template-columns: repeat(3, 1fr); }

.card {
  display: flex; flex-direction: column;
  padding: 28px; background: #fff;
  border: 1px solid var(--line); border-radius: var(--radius);
}
.card h3 { margin: 0; font-size: 22px; }
.card .tag { margin: 4px 0 12px; color: var(--brand); font-weight: 600; }
.card p { margin: 0 0 12px; }
.card pre {
  margin: 4px 0 16px; padding: 10px 14px;
  background: #f3f4f6; border-radius: 8px; overflow-x: auto;
}
.card code { font-family: Consolas, "SFMono-Regular", Menlo, monospace; font-size: 14px; }
.card .links { margin-top: auto; display: flex; gap: 20px; flex-wrap: wrap; }
.more { margin: 24px 0 0; text-align: center; color: var(--muted); }

.promo img { margin: 4px 0 16px; border-radius: 8px; border: 1px solid var(--line); }
.promo .ad { margin: 0 0 4px; font-size: 12px; color: var(--muted); }
.trade-qr { display: flex; gap: 20px; margin: 4px 0 16px; }
.trade-qr figure { flex: 1; margin: 0; text-align: center; }
.trade-qr img { width: 160px; height: auto; }
.trade-qr figcaption { font-size: 14px; color: var(--muted); }
.trade-qr figcaption b { display: block; color: var(--text); font-size: 15px; }
.btn {
  display: inline-block; padding: 8px 22px;
  background: var(--accent); color: #fff; border-radius: 999px; font-weight: 600;
}
.btn:hover { text-decoration: none; opacity: 0.9; }

.qr { align-items: center; text-align: center; }
.qr img { margin: 16px 0; }
.qr p { color: var(--muted); font-size: 14px; }


.footer {
  padding: 32px 0; text-align: center; font-size: 14px; color: var(--muted);
  border-top: 1px solid var(--line);
}
.footer p { margin: 4px 0; }
.footer a { color: var(--muted); }
.footer-links { display: flex; justify-content: center; flex-wrap: wrap; gap: 4px 20px; }
.disclaimer { font-size: 12px; }

@media (max-width: 860px) {
  .cards, .two, .three { grid-template-columns: 1fr; }
  .nav nav { gap: 14px; }
  .nav nav a:last-child { display: none; }
  .hero { padding: 56px 0 48px; }
  .hero h1 { font-size: 40px; }
  .flow { flex-direction: column; align-items: center; gap: 28px; }
  .flow li + li::before { content: "↓"; left: 50%; top: -24px; transform: translateX(-50%); }
}
@media (max-width: 600px) {
  html { scroll-padding-top: 100px; }
  .nav-inner { flex-wrap: wrap; height: auto; padding-top: 8px; padding-bottom: 8px; row-gap: 4px; }
  .nav nav { width: 100%; justify-content: space-between; gap: 0; }
  .nav nav a { font-size: 14px; }
  .brand { font-size: 19px; }
  .wrap { padding: 0 16px; }
  .card { padding: 20px; }
  .hero .lead { font-size: 19px; }
  .trade-qr { flex-direction: column; align-items: center; }
}