:root {
  --fg: #24292f;
  --muted: #57606a;
  --link: #0969da;
  --border: #d0d7de;
  --bg: #ffffff;
  --code-bg: #f6f8fa;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans",
    Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 3rem 1.25rem 4rem;
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

h1 {
  font-size: 1.9rem;
  line-height: 1.3;
  margin: 0 0 0.5rem;
}

h2 {
  font-size: 1.35rem;
  margin: 2.2rem 0 0.6rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}

h3 { font-size: 1.1rem; margin: 1.6rem 0 0.4rem; }

p { margin: 0.8rem 0; }

ul, ol { padding-left: 1.4rem; }
li { margin: 0.3rem 0; }

code {
  background: var(--code-bg);
  border-radius: 4px;
  padding: 0.15em 0.35em;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.9em;
}

pre {
  background: var(--code-bg);
  border-radius: 6px;
  padding: 0.9rem 1rem;
  overflow-x: auto;
}
pre code { background: none; padding: 0; }

blockquote {
  margin: 1rem 0;
  padding: 0.2rem 1rem;
  border-left: 3px solid var(--border);
  color: var(--muted);
}

.meta {
  color: var(--muted);
  font-size: 0.92rem;
  margin-bottom: 2rem;
}

.lang-switch {
  margin: 1rem 0 0;
  font-size: 0.95rem;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.5rem 0;
}

footer {
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: 3rem;
}