:root {
  --fg: #1a1a1f;
  --muted: #56565d;
  --bg: #ffffff;
  --surface: #f4f4f6;
  --border: #e4e4e8;
  --accent: #6f4dff;
  --max-w: 720px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 48px 24px 80px;
}

header.site {
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  font-size: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header.site a {
  color: var(--muted);
  text-decoration: none;
}

header.site a:hover {
  color: var(--accent);
}

header.site .lang {
  font-size: 13px;
}

header.site .lang a {
  margin-left: 12px;
}

h1 {
  font-size: 32px;
  margin: 0 0 8px;
  line-height: 1.2;
}

h2 {
  font-size: 22px;
  margin: 40px 0 12px;
  line-height: 1.3;
}

h3 {
  font-size: 17px;
  margin: 24px 0 8px;
}

.meta {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 32px;
}

p { margin: 12px 0; }

ul, ol { padding-left: 22px; margin: 12px 0; }
li { margin: 6px 0; }

a { color: var(--accent); }

hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 48px 0;
}

.toc {
  background: var(--surface);
  border-radius: 10px;
  padding: 16px 20px;
  margin: 24px 0 32px;
}

.toc strong {
  display: block;
  margin-bottom: 6px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.toc ol {
  margin: 0;
  padding-left: 20px;
  font-size: 14px;
}

.contact-block {
  background: var(--surface);
  border-radius: 10px;
  padding: 16px 20px;
  margin: 24px 0;
  font-size: 15px;
}

footer {
  border-top: 1px solid var(--border);
  margin-top: 64px;
  padding-top: 24px;
  font-size: 13px;
  color: var(--muted);
}

footer a {
  color: var(--muted);
  margin-right: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #ececec;
    --muted: #999;
    --bg: #0e0e12;
    --surface: #1a1a22;
    --border: #2a2a34;
    --accent: #a78bfa;
  }
}