body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

.nav-link {
  display: inline-block;
  padding: 8px 16px;
  background-color: #3498db;
  color: white;
  text-decoration: none;
  border-radius: 4px;
  margin-bottom: 20px;
}

.nav-link:hover {
  background-color: #2980b9;
}

h1 {
  color: #2c3e50;
  border-bottom: 2px solid #3498db;
  padding-bottom: 10px;
}

h2 {
  color: #2980b9;
  margin-top: 30px;
}

.feature-section {
  background: #f8f9fa;
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
}

.control-description {
  margin-bottom: 15px;
}

.control-description h3 {
  color: #34495e;
  margin-bottom: 10px;
}

.important-note {
  background: #e8f4f8;
  border-left: 4px solid #3498db;
  padding: 15px;
  margin: 20px 0;
}

ul {
  padding-left: 20px;
}

li {
  margin-bottom: 10px;
}

.footer {
  text-align: center;
  margin-top: 30px;
  padding: 20px;
  color: #666;
  border-top: 1px solid #eee;
}

.footer-content {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 15px;
}

.footer-info {
  text-align: left;
}

.footer-info p {
  margin: 5px 0;
}

.footer-links {
  display: flex;
  gap: 15px;
  align-items: center;
}

.footer-links a {
  color: #3498db;
  text-decoration: none;
  font-size: 0.9em;
}

.footer-links a:hover {
  text-decoration: underline;
  color: #2980b9;
}

.footer-divider {
  color: #ccc;
}

/* レスポンシブ対応 */
@media (max-width: 600px) {
  .header {
    grid-template-columns: 1fr;
    gap: 15px;
  }
  
  .header h1 {
    grid-column: 1;
  }
  
  .manual-link {
    grid-column: 1;
    text-align: center;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-info {
    text-align: center;
  }
  
  .footer-links {
    justify-content: center;
  }
}