:root {
  color-scheme: light;
  --ink: #1f2328;
  --ink-2: #4b5563;
  --ink-3: #8b94a3;
  --line: #e5e8ee;
  --bg: #f6f7f9;
  --card: #ffffff;
  --brand: #2c6fd1;
  --brand-2: #eef4ff;
  --warn: #b26a00;
  --ok: #157f3d;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", sans-serif;
  background: var(--bg); color: var(--ink); line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  background: #fff; border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 10;
}
.topbar-in {
  max-width: 960px; margin: 0 auto; padding: 12px 20px;
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
}
.brand { font-weight: 600; font-size: 16px; margin-right: auto; color: var(--ink); }
.brand:hover { text-decoration: none; }
.nav a {
  color: var(--ink-2); font-size: 14px; padding: 6px 10px; border-radius: 8px;
}
.nav a:hover { background: var(--brand-2); color: var(--brand); text-decoration: none; }
.nav a.on { color: var(--brand); background: var(--brand-2); }

.wrap { max-width: 960px; margin: 0 auto; padding: 28px 20px 8px; }
.card {
  background: var(--card); border-radius: 14px; padding: 30px 30px;
  border: 1px solid var(--line); margin-bottom: 16px;
}
.hero h1 { margin: 0 0 8px; font-size: 26px; letter-spacing: .3px; }
.hero .lede { margin: 0; color: var(--ink-2); font-size: 15px; }
.pill {
  display: inline-block; font-size: 12px; padding: 3px 10px; border-radius: 999px;
  background: #f0fbf4; color: var(--ok); border: 1px solid #b7ebc9; margin-top: 12px;
}
h2 {
  font-size: 16px; margin: 26px 0 10px; padding-left: 10px;
  border-left: 3px solid var(--brand);
}
h2:first-of-type { margin-top: 0; }
h3 { font-size: 14px; margin: 18px 0 6px; color: var(--ink); }
p, li, dd, dt { font-size: 14px; color: var(--ink-2); }
ul, ol { padding-left: 22px; margin: 8px 0; }
li { margin: 4px 0; }
strong { color: var(--ink); }
code {
  background: #f3f4f6; padding: 2px 6px; border-radius: 5px; font-size: 13px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: #374151;
}
pre {
  background: #f7f8fa; border: 1px solid var(--line); border-radius: 10px;
  padding: 12px 14px; overflow-x: auto; font-size: 13px; line-height: 1.6;
}
pre code { background: none; padding: 0; }

table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 14px; }
th, td {
  border: 1px solid var(--line); padding: 9px 12px; text-align: left;
  color: var(--ink-2); vertical-align: top;
}
th { background: #fafbfc; color: var(--ink); font-weight: 500; }
td.num, th.num { text-align: right; white-space: nowrap; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.tile {
  border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; background: #fcfdfe;
}
.tile h3 { margin: 0 0 4px; font-size: 14px; }
.tile p { margin: 0; font-size: 13px; color: var(--ink-2); }

.note {
  border-left: 3px solid #f0c36d; background: #fffaf0; color: #6b5320;
  padding: 10px 14px; border-radius: 0 8px 8px 0; font-size: 13px; margin: 12px 0;
}
.note b { color: #5a4418; }
.btn {
  display: inline-block; background: var(--brand); color: #fff; font-size: 14px;
  padding: 10px 22px; border-radius: 10px; border: none; cursor: pointer;
}
.btn:hover { background: #245cb0; text-decoration: none; }
.btn.ghost { background: #fff; color: var(--brand); border: 1px solid #c9dcf7; }
.btn.ghost:hover { background: var(--brand-2); }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }

footer {
  max-width: 960px; margin: 8px auto 0; padding: 22px 20px 34px;
  text-align: center; font-size: 12px; color: var(--ink-3); line-height: 1.9;
}
footer a { color: var(--ink-3); border-bottom: 1px dotted #cbd2dc; }
footer a:hover { text-decoration: none; color: var(--ink-2); }

@media (max-width: 640px) {
  .card { padding: 22px 18px; }
  .hero h1 { font-size: 22px; }
  th, td { padding: 8px 9px; font-size: 13px; }
}