:root {
  --yudun-ink: #142033;
  --yudun-muted: #566578;
  --yudun-line: #dbe3e8;
  --yudun-brand: #0f6b78;
  --yudun-soft: #eef7f5;
  --yudun-canvas: #f4f7f8;
}

body {
  background: var(--yudun-canvas);
  color: var(--yudun-ink);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
}

.top {
  background: rgba(255, 255, 255, 0.96);
  border-bottom-color: var(--yudun-line);
}

.nav {
  min-height: 74px;
  height: auto;
  padding: 12px 0;
}

.brand {
  color: var(--yudun-ink);
  font-size: 19px;
  letter-spacing: 0;
}

.brand::before {
  content: "";
  display: inline-block;
  width: 9px;
  height: 9px;
  margin-right: 8px;
  border: 2px solid var(--yudun-brand);
  border-radius: 2px;
  vertical-align: 1px;
}

.nav-links {
  gap: 5px 16px;
  align-items: center;
}

.nav-links a {
  color: #405064;
  font-weight: 600;
  transition: color .16s ease;
}

.nav-links a:hover {
  color: var(--yudun-brand);
}

.nav-links a:last-child {
  border: 1px solid #b8dad4;
  border-radius: 7px;
  padding: 7px 10px;
  color: #075b67;
  background: #f5fbfa;
}

.hero {
  padding: 72px 0 42px;
  background: #fbfcfc;
  border-bottom: 1px solid var(--yudun-line);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--yudun-brand);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .1em;
}

.kicker::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--yudun-brand);
}

.hero h1 {
  max-width: 820px;
  margin: 17px 0;
  color: var(--yudun-ink);
  font-size: clamp(38px, 4.8vw, 56px);
  line-height: 1.16;
  letter-spacing: 0;
}

.lead {
  max-width: 850px;
  color: #334458;
  font-size: 18px;
  line-height: 1.85;
}

.intent {
  max-width: 880px;
  margin-top: 24px;
  padding: 14px 16px;
  border: 1px solid #cce4df;
  border-left: 3px solid var(--yudun-brand);
  border-radius: 7px;
  background: var(--yudun-soft);
  color: #31505a;
  font-size: 15px;
  line-height: 1.75;
}

main.shell {
  padding: 34px 0 72px;
}

.panel {
  margin: 14px 0;
  padding: 26px;
  border: 1px solid var(--yudun-line);
  border-radius: 9px;
  background: #fff;
  box-shadow: 0 1px 2px rgba(15, 23, 42, .025);
}

.panel h2 {
  margin-bottom: 12px;
  color: var(--yudun-ink);
  font-size: 24px;
  line-height: 1.35;
}

.panel h3 {
  color: var(--yudun-ink);
  font-size: 17px;
}

.panel p {
  color: var(--yudun-muted);
  line-height: 1.85;
}

.grid {
  gap: 12px;
}

.grid article {
  padding: 18px;
  border: 1px solid #d8e9e5;
  border-radius: 7px;
  background: #f7fbfa;
}

.faq-list details {
  border-color: var(--yudun-line);
}

.faq-list summary {
  color: var(--yudun-ink);
}

.faq-list summary:hover {
  color: var(--yudun-brand);
}

.link-list {
  gap: 8px;
}

.link-list a {
  padding: 9px 12px;
  border-color: #bddbd5;
  border-radius: 7px;
  color: #075b67;
  background: #f8fcfb;
  font-size: 14px;
  font-weight: 700;
  transition: background .16s ease, border-color .16s ease;
}

.link-list a:hover {
  border-color: var(--yudun-brand);
  background: #e8f4f2;
}

.conversion-cta {
  border-radius: 7px;
  background: var(--yudun-brand);
  box-shadow: 0 2px 4px rgba(15, 107, 120, .18);
}

.conversion-cta:hover {
  background: #0b5863;
}

.footer {
  padding: 34px 0;
  background: #142033;
}

@media (max-width: 720px) {
  .nav {
    display: block;
    min-height: 0;
    padding: 12px 0;
  }

  .nav-links {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    width: 100%;
    gap: 4px 0;
    margin-top: 10px;
  }

  .nav-links a {
    display: flex;
    min-width: 0;
    min-height: 32px;
    align-items: center;
    justify-content: center;
    white-space: nowrap;
    font-size: 13px;
  }

  .nav-links a:last-child { padding: 5px 7px; }

  .hero {
    padding: 46px 0 32px;
  }

  .hero h1 {
    font-size: 36px;
  }

  .lead {
    font-size: 17px;
  }

  .panel {
    padding: 20px;
  }

  .panel h2 {
    font-size: 21px;
  }
}