:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body {
  font-family: -apple-system, Roboto, "Segoe UI", system-ui, sans-serif;
  line-height: 1.55;
  margin: 0;
  padding: 20px 18px 40px;
  color: #1b1b1f;
  background: #ffffff;
  font-size: 15px;
}
@media (prefers-color-scheme: dark) {
  body { color: #e3e2e6; background: #141821; }
  a { color: #8ab4f8; }
  .muted { color: #b0b6c0; }
}
h1 { font-size: 20px; margin: 0 0 4px; }
h2 { font-size: 16px; margin: 22px 0 6px; }
p, li { font-size: 15px; }
ul { padding-left: 20px; }
.muted { color: #5f6368; font-size: 13px; }
.note { border-left: 3px solid #8ab4f8; padding: 8px 12px; margin: 14px 0; background: rgba(138,180,248,0.10); font-size: 13px; }