body {
    margin: 0;
    font-family: 'Helvetica Neue', sans-serif;
    background-color: #f8f8f8;
    color: #333;
  }
  
  #wrap {
    max-width: 960px;
    margin: 0 auto;
    padding: 20px;
  }
  
  header {
    text-align: center;
  }
  
  header h1 a {
    text-decoration: none;
    color: #000;
  }
  
  nav ul {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    gap: 20px;
  }
  
  nav ul li a {
    text-decoration: none;
    color: #333;
  }
  
  main {
    padding: 1rem;
    margin: 0 auto;
    max-width: 1200px;
    display: block;
  }
  
  footer {
    text-align: center;
    padding: 20px;
    font-size: 0.9em;
    color: #777;
  }
  
  .container {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 20px;
  }
  
  @media screen and (min-width: 768px) {
    .sec01,
    .sec02,
    .sec03 {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }
  }