:root {
  --bg: #f5f5fb;
  --card: #ffffff;
  --text: #1c1b2e;
  --muted: #5f5d75;
  --line: #e4e3f1;
  --primary: #5b5bf0;
  --primary-soft: #e6e6fd;
  --danger: #e5484d;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12121f;
    --card: #1c1b2e;
    --text: #f1f0fb;
    --muted: #a9a7c2;
    --line: #2d2c44;
    --primary: #8585ff;
    --primary-soft: #2a2a55;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 48px; }
header.brand { display: flex; align-items: center; gap: 12px; margin-bottom: 24px; }
.logo {
  width: 44px; height: 44px; border-radius: 12px;
  background: var(--primary); color: #fff;
  display: grid; place-items: center; font-weight: 800; font-size: 20px;
}
.brand b { font-size: 22px; }
h1 { font-size: 30px; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 28px 0 8px; }
p, li { color: var(--muted); }
strong { color: var(--text); }
a { color: var(--primary); }
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 16px; padding: 20px; margin: 16px 0;
}
.button {
  display: inline-block; text-decoration: none; font-weight: 600;
  background: var(--primary); color: #fff; border-radius: 999px;
  padding: 12px 22px; margin: 6px 8px 6px 0;
}
.button.soft { background: var(--primary-soft); color: var(--primary); }
.code {
  display: inline-block; font: 700 22px/1 ui-monospace, monospace; letter-spacing: 3px;
  background: var(--primary-soft); color: var(--primary);
  padding: 10px 16px; border-radius: 12px;
}
footer { margin-top: 40px; font-size: 14px; color: var(--muted); }
footer a { margin-right: 14px; }