:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1c1c1e;
  --muted: #6e6e73;
  --accent: #d7263d;
  --border: #e5e5ea;
  --card: #f7f7f8;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0e10;
    --fg: #f2f2f3;
    --muted: #a1a1a6;
    --accent: #ff4d5e;
    --border: #2c2c2e;
    --card: #18181b;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
}

header {
  padding: 24px 20px;
  border-bottom: 1px solid var(--border);
}

header .wrap {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header a.brand {
  font-weight: 700;
  font-size: 18px;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: -0.01em;
}

header nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 15px;
  margin-left: 20px;
}

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

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}

h1 {
  font-size: 30px;
  margin: 0 0 4px;
  letter-spacing: -0.01em;
}

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

h2 {
  font-size: 19px;
  margin-top: 36px;
  margin-bottom: 10px;
}

p, li {
  font-size: 16px;
  color: var(--fg);
}

ul {
  padding-left: 22px;
}

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

.intro {
  color: var(--muted);
  font-size: 16px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 20px 0;
}

footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px;
  color: var(--muted);
  font-size: 13px;
  border-top: 1px solid var(--border);
}