:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --text: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #f8fafc;
  --card: #ffffff;
  --sidebar: #0f172a;
  --max: 880px;
}

* {
  box-sizing: border-box;
}

html {
  color: var(--text);
  background: var(--bg);
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  line-height: 1.65;
  font-size: 16px;
}

body {
  margin: 0;
}

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

a:hover {
  text-decoration: underline;
}

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 20px;
}

header {
  background: var(--card);
  border-bottom: 1px solid var(--line);
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
  flex-wrap: wrap;
  padding: 8px 0;
}

.brand {
  color: var(--sidebar);
  font-weight: 700;
  font-size: 18px;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand span {
  display: block;
  font-weight: 400;
  font-size: 12px;
  color: var(--muted);
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  font-size: 14px;
}

nav a {
  color: var(--text);
}

nav a[aria-current="page"] {
  color: var(--primary);
  font-weight: 600;
}

.lang {
  font-size: 13px;
  color: var(--muted);
}

main {
  padding: 40px 0 56px;
}

h1 {
  font-size: 28px;
  line-height: 1.3;
  margin: 0 0 12px;
  color: var(--sidebar);
}

h2 {
  font-size: 20px;
  margin: 32px 0 12px;
  color: var(--sidebar);
}

.lede {
  color: var(--muted);
  margin: 0 0 24px;
  max-width: 42em;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 20px 22px;
  margin: 12px 0;
}

.card h2 {
  margin-top: 0;
}

ul {
  margin: 8px 0 0;
  padding-left: 1.2em;
}

li {
  margin: 6px 0;
}

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

dl {
  margin: 0;
}

dt {
  color: var(--muted);
  font-size: 13px;
  margin-top: 14px;
}

dd {
  margin: 2px 0 0;
}

footer {
  border-top: 1px solid var(--line);
  background: var(--card);
  padding: 24px 0 32px;
  font-size: 13px;
  color: var(--muted);
}

footer p {
  margin: 0 0 6px;
}

footer .legal-links a {
  margin-right: 12px;
}