:root {
  --bg: #f6faf7;
  --surface: #ffffff;
  --ink: #15201a;
  --muted: #5b6b62;
  --accent: #0e9f5a;
  --line: #dbe7df;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1612;
    --surface: #17211b;
    --ink: #e8f1eb;
    --muted: #a3b4aa;
    --accent: #3ddc84;
    --line: #26332b;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
}
main { max-width: 720px; margin: 0 auto; padding: 40px 16px 64px; }
header { display: flex; align-items: center; gap: 14px; margin-bottom: 28px; }
header .mark {
  width: 52px; height: 52px; border-radius: 12px; background: var(--accent);
  display: grid; place-items: center; color: #fff; font-size: 28px;
}
h1 { font: 700 30px/1.15 -apple-system, BlinkMacSystemFont, "SF Pro Rounded", sans-serif; margin: 0; }
header p { margin: 2px 0 0; color: var(--muted); }
h2 { font-size: 21px; margin: 36px 0 8px; }
h3 { font-size: 17px; margin: 22px 0 4px; }
section { background: var(--surface); border: 1px solid var(--line); border-radius: 18px; padding: 4px 22px 18px; margin: 18px 0; }
a { color: var(--accent); }
nav { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 8px; }
.lang { color: var(--muted); font-size: 15px; }
footer { color: var(--muted); font-size: 14px; margin-top: 40px; }
ul { padding-left: 20px; }