:root {
  --fg: #1c1c1e;
  --muted: #6b6b70;
  --line: #e3e3e6;
  --bg: #fdfdfc;
  --link: #1a5fb4;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

header {
  max-width: 720px;
  margin: 0 auto;
  padding: 28px 24px 20px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}

.brand {
  font-weight: 600;
  font-size: 17px;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: .02em;
}

nav a {
  margin-left: 20px;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
}

nav a:hover { color: var(--fg); }

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px 72px;
}

h1 {
  font-size: 28px;
  font-weight: 600;
  margin: 0 0 8px;
  letter-spacing: -.01em;
}

.lede {
  color: var(--muted);
  margin: 0 0 44px;
  font-size: 15px;
}

.post { margin-bottom: 36px; }

.post h2 {
  font-size: 18px;
  font-weight: 600;
  margin: 0 0 6px;
}

.post h2 a {
  color: var(--fg);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.post h2 a:hover { border-bottom-color: var(--line); }

.meta {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 8px;
  font-variant-numeric: tabular-nums;
}

.post p { margin: 0; color: #3a3a3f; font-size: 15px; }

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

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .9em;
  background: #f2f2f4;
  padding: 1px 5px;
  border-radius: 3px;
}

footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

article.body h1 { margin-bottom: 6px; }
article.body { max-width: 720px; }
article.body p { font-size: 16px; line-height: 1.8; margin: 0 0 18px; color: #2c2c31; }
article.body h2 { font-size: 19px; margin: 32px 0 12px; }
article.body ul { padding-left: 22px; }
article.body li { margin-bottom: 8px; }

@media (max-width: 600px) {
  header { flex-direction: column; gap: 10px; padding-top: 20px; }
  nav a:first-child { margin-left: 0; }
  main { padding-top: 28px; }
}