:root {
  color-scheme: light dark;
  --bg: #0d1117;
  --panel: #161b22;
  --text: #f0f3f6;
  --muted: #9da7b3;
  --line: #30363d;
  --accent: #5fd0a5;
  --link: #72b7ff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}
header, main, footer {
  width: min(900px, calc(100% - 40px));
  margin: 0 auto;
}
header {
  padding: 28px 0 18px;
  border-bottom: 1px solid var(--line);
}
.brand {
  color: var(--text);
  text-decoration: none;
  font-size: 1.35rem;
  font-weight: 750;
}
nav { margin-top: 10px; }
nav a { margin-right: 18px; }
main { padding: 36px 0 56px; }
h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.15; }
h2 { margin-top: 2rem; font-size: 1.35rem; }
a { color: var(--link); }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px;
  margin: 22px 0;
}
.notice {
  border-left: 4px solid var(--accent);
  padding-left: 16px;
}
.muted { color: var(--muted); }
footer {
  border-top: 1px solid var(--line);
  padding: 24px 0 48px;
  color: var(--muted);
  font-size: 0.92rem;
}
ul { padding-left: 22px; }