:root {
  --bg: #fdfcfa;
  --text: #2b2b2b;
  --muted: #6b6b6b;
  --accent: #1f4e5f;
  --accent-soft: #eef4f6;
  --border: #e4e0da;
  --max-width: 720px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic UI",
    "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

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

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.1rem 1.5rem;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
  text-decoration: none;
}

nav {
  display: flex;
  gap: 1.25rem;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
}

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

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
}

h1 {
  font-size: 1.7rem;
  line-height: 1.4;
  margin: 0 0 1rem;
}

h2 {
  font-size: 1.15rem;
  margin: 2.5rem 0 0.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

p {
  margin: 0.75rem 0;
}

.lead {
  color: var(--muted);
  font-size: 1.02rem;
}

.card {
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
}

.card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  color: var(--accent);
}

.card p {
  margin: 0.3rem 0;
  font-size: 0.95rem;
}

ul {
  padding-left: 1.4rem;
}

li {
  margin: 0.35rem 0;
}

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

dl {
  margin: 1rem 0;
}

dt {
  font-weight: 600;
  margin-top: 1rem;
}

dd {
  margin: 0.25rem 0 0 1rem;
  color: var(--muted);
}

.meta {
  color: var(--muted);
  font-size: 0.88rem;
}

footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
}

footer a {
  color: var(--muted);
  margin: 0 0.5rem;
}

@media (max-width: 480px) {
  .header-inner {
    flex-direction: column;
    gap: 0.4rem;
  }
}