:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1c2330;
  --muted: #5b6575;
  --line: #e3e6eb;
  --accent: #1a73e8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12151b;
    --card: #1b2029;
    --text: #e8ebf0;
    --muted: #a3acba;
    --line: #2a313d;
    --accent: #8ab4f8;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.wrap { max-width: 720px; margin: 0 auto; padding: 40px 16px 56px; }
header { margin-bottom: 28px; }
.logo {
  width: 56px; height: 56px; border-radius: 14px;
  background: var(--accent); color: #fff;
  display: grid; place-items: center;
  font-weight: 700; font-size: 22px; letter-spacing: .5px;
  margin-bottom: 16px;
}
h1 { font-size: 28px; line-height: 1.25; margin: 0 0 6px; }
h2 { font-size: 19px; margin: 0 0 8px; }
h3 { font-size: 16px; margin: 20px 0 4px; }
p, li { color: var(--text); }
.sub { color: var(--muted); margin: 0; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
  margin-bottom: 16px;
}
.card p:last-child, .card ul:last-child { margin-bottom: 0; }
a { color: var(--accent); }
ul { padding-left: 20px; }
footer { color: var(--muted); font-size: 14px; margin-top: 32px; }
footer a { color: var(--muted); }