:root {
  color-scheme: light;
  --bg: #f4f8fb;
  --card: #ffffff;
  --ink: #1a2433;
  --muted: #4d5b70;
  --line: #d8e1ea;
  --primary: #0a6d7f;
  --primary-soft: #e5f4f8;
  --accent: #1e4f9e;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 0% 0%, #e8f7ff 0%, transparent 40%),
    radial-gradient(circle at 100% 0%, #eef5ff 0%, transparent 36%),
    var(--bg);
  min-height: 100vh;
}

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

a:hover {
  text-decoration: underline;
}

.site-shell {
  max-width: 1080px;
  margin: 0 auto;
  padding: 20px;
}

.topbar {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px 16px;
  display: flex;
  gap: 14px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  box-shadow: 0 8px 18px rgba(20, 34, 58, 0.05);
}

.brand {
  font-weight: 700;
  color: var(--primary);
}

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

.topnav a {
  display: inline-block;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #fbfdff;
  color: var(--ink);
  font-size: 0.92rem;
}

.topnav a.active {
  border-color: var(--primary);
  background: var(--primary-soft);
  color: var(--primary);
  font-weight: 600;
}

.main-card {
  margin-top: 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 22px;
  box-shadow: 0 12px 26px rgba(20, 34, 58, 0.06);
}

.badge {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  background: var(--primary-soft);
  color: var(--primary);
}

h1 {
  margin: 12px 0;
  font-size: 1.7rem;
}

h2 {
  margin: 0 0 10px;
  font-size: 1.15rem;
}

p {
  margin: 10px 0;
  color: var(--muted);
  line-height: 1.6;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 14px;
}

.panel {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px;
  background: #fcfeff;
}

.list {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

.notice {
  margin-top: 12px;
  border: 1px solid #bcd9e0;
  background: #eef9fb;
  border-radius: 12px;
  padding: 10px 12px;
  color: #20586b;
  font-size: 0.92rem;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
  background: #fff;
  margin-bottom: 10px;
}

.faq-item summary {
  font-weight: 600;
  cursor: pointer;
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 10px;
}

.support-grid .panel strong {
  display: block;
  margin-bottom: 6px;
}

.footer {
  margin-top: 12px;
  color: #6a7a90;
  font-size: 0.86rem;
}

@media (max-width: 860px) {
  .grid,
  .support-grid {
    grid-template-columns: 1fr;
  }
}