:root {
  --bg: #f4f7fc;
  --surface: #ffffff;
  --line: #d6dceb;
  --ink: #0e1f43;
  --muted: #4f5f7b;
  --primary: #12306a;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: linear-gradient(180deg, #f9fbff 0%, var(--bg) 45%, #eef2f8 100%);
  font-family: "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

a { color: var(--primary); text-decoration: none; }

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid rgba(18, 48, 106, 0.45);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 10px;
  z-index: 20;
  padding: 8px 12px;
  border-radius: 8px;
  background: #0c2350;
  color: #fff;
  font-size: 14px;
}

.skip-link:focus { top: 10px; }

.container {
  width: min(980px, 92vw);
  margin: 0 auto;
}

.topbar {
  border-bottom: 1px solid rgba(18, 48, 106, 0.12);
  background: rgba(249, 251, 255, 0.92);
}

.topbar-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 21px;
  font-weight: 800;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 8px;
}

.nav {
  display: inline-flex;
  gap: 16px;
  color: var(--muted);
  font-size: 14px;
}

main { padding: 36px 0 64px; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 8px 24px rgba(11, 31, 72, 0.08);
}

h1 {
  margin: 0 0 14px;
  font-size: clamp(30px, 4vw, 44px);
}

h2 {
  margin: 0 0 10px;
  font-size: clamp(22px, 2.6vw, 30px);
}

p, li {
  color: var(--muted);
  line-height: 1.75;
  font-size: 16px;
}

.section {
  margin-top: 20px;
}

.faq-item {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fcfdff;
}

.faq-item + .faq-item {
  margin-top: 12px;
}

.faq-q {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 18px;
  font-weight: 700;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  display: inline-block;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #f7faff;
  color: var(--ink);
  font-size: 14px;
}

.footer {
  margin-top: 24px;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 640px) {
  .topbar-inner {
    min-height: 62px;
  }

  .nav {
    gap: 10px;
    font-size: 13px;
  }

  .card {
    padding: 18px;
  }

  p, li {
    font-size: 15px;
  }
}