:root {
  --bg: #f7f5ef;
  --surface: #ffffff;
  --text: #2f3437;
  --muted: #646d73;
  --primary: #1f4d3a;
  --primary-soft: #e7efe9;
  --border: #d8ddd9;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
}

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

.container {
  width: min(1080px, 92%);
  margin: 0 auto;
}

header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
}

.brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.03em;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 0.6rem 1rem;
}

.nav-links a {
  color: var(--text);
  font-size: 0.95rem;
}

main { padding: 2rem 0 3.5rem; }

.hero {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 2.2rem;
}

h1, h2, h3 {
  line-height: 1.4;
  margin-top: 0;
}

h1 { font-size: clamp(1.6rem, 3.3vw, 2.4rem); }
h2 { font-size: clamp(1.25rem, 2.3vw, 1.7rem); margin-top: 2.2rem; }

.lead {
  font-size: 1.05rem;
  color: var(--muted);
}

.grid {
  margin-top: 1.5rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.1rem;
}

.highlight {
  background: var(--primary-soft);
  border-left: 4px solid var(--primary);
  padding: 1rem 1.1rem;
  border-radius: 6px;
}

.section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  margin-top: 1.2rem;
}

dl {
  margin: 0;
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 0.7rem 1rem;
}

dt { font-weight: 700; }

dd { margin: 0; }

ul { padding-left: 1.2rem; }

footer {
  background: #eceeea;
  border-top: 1px solid var(--border);
  padding: 1.3rem 0 2rem;
  font-size: 0.92rem;
  color: #52595d;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  list-style: none;
  padding: 0;
  margin: 0.4rem 0 0;
}

@media (max-width: 860px) {
  .grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .nav { align-items: flex-start; flex-direction: column; }
  .grid { grid-template-columns: 1fr; }
  .hero { padding: 1.4rem; }
  dl { grid-template-columns: 1fr; gap: 0.3rem; }
}