:root {
  --bg: #ffffff;
  --text: #1a1d21;
  --muted: #5c6470;
  --accent: #3d6bff;
  --border: #e4e7ec;
  --card: #f7f8fa;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1013;
    --text: #e8eaed;
    --muted: #9aa3af;
    --accent: #7c9aff;
    --border: #262b33;
    --card: #171a1f;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}
h1 { font-size: 1.9em; line-height: 1.25; margin: 0.2em 0 0.4em; }
h2 { font-size: 1.25em; margin: 1.8em 0 0.5em; }
p, li { color: var(--text); }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.meta { color: var(--muted); font-size: 0.92em; margin-bottom: 2em; }
.summary {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
  margin: 1.4em 0;
}
.footer {
  margin-top: 3.5em;
  padding-top: 1.5em;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9em;
}
.lang { float: right; font-size: 0.9em; }
ul { padding-left: 1.3em; }
strong { font-weight: 600; }
.brand { font-weight: 700; letter-spacing: 0.2px; }