:root {
  --primary: #3b6ef5;
  --text: #1f2329;
  --text-sub: #5f6673;
  --bg: #f7f8fa;
  --card: #ffffff;
  --border: #e8eaef;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  font-size: 16px;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 24px 20px 60px; }
header.site {
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
header.site .inner {
  max-width: 760px; margin: 0 auto; padding: 14px 20px;
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px;
}
.brand { font-weight: 700; font-size: 17px; color: var(--text); text-decoration: none; }
.brand span { color: var(--primary); }
nav.top a {
  color: var(--text-sub); text-decoration: none; font-size: 14px; margin-left: 16px;
}
nav.top a:hover { color: var(--primary); }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  padding: 32px 28px; margin-top: 24px;
}
h1 { font-size: 24px; margin-bottom: 8px; }
.meta { color: var(--text-sub); font-size: 13px; margin-bottom: 24px; }
h2 { font-size: 18px; margin: 28px 0 10px; }
h3 { font-size: 16px; margin: 18px 0 8px; }
p { margin: 10px 0; }
ul, ol { margin: 10px 0 10px 22px; }
li { margin: 6px 0; }
strong { font-weight: 600; }
a { color: var(--primary); }
table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 14px; }
th, td { border: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
th { background: var(--bg); }
.tip {
  background: #eef3ff; border: 1px solid #d5e0fb; border-radius: 8px;
  padding: 12px 16px; font-size: 14px; color: #33549e; margin: 14px 0;
}
footer.site {
  max-width: 760px; margin: 0 auto; padding: 24px 20px 40px;
  color: var(--text-sub); font-size: 13px; text-align: center;
}
footer.site a { color: var(--text-sub); margin: 0 8px; }
@media (max-width: 480px) {
  .card { padding: 24px 18px; }
  nav.top a { margin-left: 10px; }
}