:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --ink: #1d2433;
  --muted: #5d6677;
  --line: #e2e5ea;
  --blue: #2563eb;
  --blue-ink: #ffffff;
  --warn: #b42318;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --card: #1d2026;
    --ink: #e9ecf1;
    --muted: #a3abb8;
    --line: #2e333b;
    --blue: #5b8cff;
    --blue-ink: #0b1020;
    --warn: #ff8a7a;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 17px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 720px; margin: 0 auto; padding: 40px 16px 64px; }
header.site { display: flex; align-items: center; gap: 12px; margin-bottom: 28px; }
header.site img { width: 44px; height: 44px; border-radius: 10px; }
header.site a { color: inherit; text-decoration: none; font-weight: 700; font-size: 22px; }
h1 { font-size: 30px; line-height: 1.2; margin: 0 0 12px; }
h2 { font-size: 20px; margin: 32px 0 8px; }
p, li { color: var(--ink); }
.muted { color: var(--muted); }
a { color: var(--blue); }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px;
  margin: 18px 0;
}
.button {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 48px; padding: 0 22px;
  border: 0; border-radius: 12px;
  background: var(--blue); color: var(--blue-ink);
  font: inherit; font-weight: 600; text-decoration: none; cursor: pointer;
}
.button.quiet { background: transparent; color: var(--blue); border: 1px solid var(--line); }
.button[disabled] { opacity: .55; cursor: default; }
.button svg { width: 24px; height: 22px; flex: none; }
footer.site { margin-top: 48px; padding-top: 16px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
footer.site a { color: var(--muted); }
code { font-size: 0.92em; }