:root {
  --bg: #fbfbfa;
  --fg: #1f2124;
  --muted: #6b7076;
  --line: #e3e3e0;
  --accent: #2f5fd0;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181b;
    --fg: #e6e7e8;
    --muted: #9aa0a6;
    --line: #2c2f33;
    --accent: #7ea6f5;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Helvetica Neue", Arial, "Hiragino Sans", "Yu Gothic UI", Meiryo, sans-serif;
  line-height: 1.85;
  font-size: 16px;
}

main {
  max-width: 42rem;
  margin: 0 auto;
  padding: 4.5rem 1.5rem 6rem;
}

h1 {
  font-size: 1.75rem;
  letter-spacing: -0.01em;
  margin: 0 0 1.25rem;
}

h2 {
  font-size: 1.0625rem;
  margin: 2.75rem 0 0.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

p { margin: 0 0 1rem; }

.lead {
  color: var(--muted);
  margin-bottom: 2rem;
}

ul {
  margin: 0 0 1rem;
  padding-left: 1.25rem;
}

li { margin-bottom: 0.35rem; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
}

a:hover { border-bottom-color: var(--accent); }

code {
  font-family: "SF Mono", Consolas, "Courier New", monospace;
  font-size: 0.875em;
  background: color-mix(in srgb, var(--fg) 7%, transparent);
  padding: 0.1em 0.4em;
  border-radius: 3px;
}

.back {
  margin-bottom: 2.5rem;
  font-size: 0.875rem;
}

.updated {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.875rem;
}