:root {
  --ink: #1d2733;
  --muted: #5d6b7a;
  --line: #d9dfe6;
  --paper: #ffffff;
  --page: #f4f6f8;
  --accent: #1f5f8b;
  --good: #1e7a46;
  --bad: #b3261e;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}
.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.top form { display: flex; align-items: center; gap: 12px; margin: 0; }
.brand { color: var(--ink); font-weight: 600; text-decoration: none; }
.who { color: var(--muted); }
main { max-width: 720px; margin: 0 auto; padding: 16px; }
h1 { font-size: 1.5rem; margin: 16px 0; }
h2 { font-size: 1.1rem; margin: 0 0 8px; }
section {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
}
a { color: var(--accent); }
code { font-family: ui-monospace, Menlo, Consolas, monospace; }
.facts { display: grid; grid-template-columns: max-content 1fr; gap: 8px 16px; margin: 0; }
.facts dt { color: var(--muted); }
.facts dd { margin: 0; }
.note { color: var(--muted); margin-left: 8px; }
.good { color: var(--good); font-weight: 600; }
.bad { color: var(--bad); font-weight: 600; }
.login { display: grid; gap: 8px; max-width: 360px; }
input[type="text"], input[type="password"] {
  font: inherit;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  width: 100%;
}
button {
  font: inherit;
  padding: 10px 16px;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}
button.link { background: none; color: var(--accent); padding: 0; text-decoration: underline; }
.login button { margin-top: 8px; }
@media (max-width: 480px) {
  .facts { grid-template-columns: 1fr; gap: 2px; }
  .facts dd { margin-bottom: 10px; }
  .note { display: block; margin-left: 0; }
}