*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  color: #333;
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
header {
  border-bottom: 1px solid #e5e7eb;
  padding: 0 24px;
}

nav {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: #333;
  text-decoration: none;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 24px;
}

nav ul a {
  color: #555;
  text-decoration: none;
  font-size: 0.9rem;
}

nav ul a:hover {
  color: #000;
}

/* Hero */
.hero {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.hero p {
  font-size: 1.2rem;
  color: #666;
}

/* Content pages */
main.content {
  flex: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px;
  width: 100%;
}

main.content h1 {
  font-size: 1.8rem;
  margin-bottom: 8px;
}

.last-updated {
  color: #888;
  font-size: 0.85rem;
  margin-bottom: 40px;
}

main.content section {
  margin-bottom: 32px;
}

main.content h2 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid #e5e7eb;
}

main.content p {
  margin-bottom: 12px;
}

/* Footer */
footer {
  border-top: 1px solid #e5e7eb;
  padding: 24px;
  text-align: center;
  color: #888;
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 600px) {
  .hero h1 {
    font-size: 2rem;
  }

  nav ul {
    gap: 16px;
  }
}