.back-fixed-button {
    position: fixed;
    bottom: 20px;
    left: 20px;
    padding: 10px 20px;
    background-color: #fc9db5;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    transition: background-color 0.3s ease;
    z-index: 1000;
    text-decoration: none; /* ★ 下線を消す！ */
    display: inline-block;  /* ボタンの見た目を整えるために追加 */
  }
  
  .back-fixed-button:hover {
    background-color: #e5889f;
  }

  /* ===== 全体リセット・基本スタイル ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    background-color: #fff;
    color: #333;
    padding: 20px;
  }
  
  /* ===== ナビバー ===== */
  .navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: white;
    z-index: 1000;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    padding: 1em 1.5em;
    border-bottom: 1px solid #ccc;
  }
  
  .menu-toggle {
    font-size: 28px;
    cursor: pointer;
    padding: 5px 10px;
    user-select: none;
  }
  
  #menu-icon {
    transition: transform 0.3s ease;
  }
  
  .nav-menu {
    list-style: none;
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transition: max-height 0.4s ease, opacity 0.4s ease;
    flex-direction: column;
    background-color: white;
    position: absolute;
    top: 60px;
    right: 20px;
    border: 1px solid #ccc;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    width: 200px;
  }
  
  .nav-menu.active {
    max-height: 300px;
    opacity: 1;
  }
  
  .nav-menu li {
    margin: 10px 20px;
  }
  
  .nav-menu a {
    color: black;
    text-decoration: none;
    font-size: 18px;
    transition: color 0.3s;
    display: block;
    padding: 8px 0;
  }
  
  .nav-menu a:hover {
    color: #fc9db5;
  }
  
  /* ===== 画像センター配置用 ===== */
  .image-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 120px;
  }
  
  .center-image {
    max-width: 90%;
    height: auto;
    border-radius: 10px;
  }
  
  /* ===== フッター ===== */
  .footer {
    position: fixed;
    bottom: 0;
    left: 0;
    background-color: #f8f8f8;
    border: 1px solid #ccc;
    padding: 20px;
    font-size: 14px;
    color: #666;
    width: 100%;
    display: flex;
    justify-content: flex-end;
    align-items: flex-end;
    height: 80px;
    box-sizing: border-box;
  }
  
  /* ===== フェードイン（再利用可能） ===== */
  .fade-in {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeIn 1.2s ease-out forwards;
  }
  
  @keyframes fadeIn {
    to {
      opacity: 1;
      transform: none;
    }
  }
  
  /* ===== スマホ対応（レスポンシブ） ===== */
  @media screen and (max-width: 768px) {
    .navbar {
      justify-content: space-between;
      padding: 0.8em 1em;
    }
  
    .menu-toggle {
      font-size: 26px;
      padding: 8px 12px;
    }
  
    .nav-menu {
      top: 56px;
      right: 10px;
      width: 180px;
    }
  
    .nav-menu li {
      margin: 8px 16px;
    }
  
    .nav-menu a {
      font-size: 16px;
      padding: 6px 0;
    }
  
    .image-container {
      margin-top: 80px;
    }
  
    .footer {
      font-size: 12px;
      padding: 15px;
      height: 70px;
    }
  }