/* styles.css */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
}

.navbar {
    background-color: #4a90e2;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-links {
    display: flex;
    gap: 1rem;
}

.nav-item {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

.nav-item:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.search-section {
    padding: 2rem;
    background-color: #f5f5f5;
    text-align: center;
}

.search-form {
    display: flex;
    gap: 1rem;
    max-width: 800px;
    margin: 1rem auto;
}

.search-form input,
.search-form select {
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    flex: 1;
}

.search-form button {
    padding: 0.5rem 2rem;
    background-color: #4a90e2;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.featured-books {
    padding: 2rem;
}

.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    padding: 1rem;
}

footer {
    background-color: #333;
    color: white;
    padding: 1rem;
    text-align: center;
    margin-top: 2rem;
}

/* 教科書一覧 */
.book-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}
.product-card {
  background-color: #fff;
  width: calc(25% - 20px);
  border: 1px solid #ddd;
  border-radius: 8px;
  overflow: hidden;
  text-align: center;
  padding-bottom: 10px;
}
.product-card img {
  width: 100%;
  height: auto;
}
.product-card h3 {
  margin: 10px 0;
}
.product-card .author {
  font-size: 0.9em;
  color: #555;
}
.product-card .price {
  font-size: 1.2em;
  color: #e74c3c;
}

/* ボタン共通 */
.btn {
  display: inline-block;
  padding: 8px 16px;
  background-color: #3498db;
  color: #fff;
  text-decoration: none;
  margin-top: 10px;
  border-radius: 4px;
}
.btn:hover {
  background-color: #2980b9;
}



/* 追加メディアクエリ */

/* スマートフォン向けの基本設定 */
@media screen and (max-width: 768px) {
    /* ナビゲーション */
    .navbar {
      flex-direction: column;
      padding: 0.5rem;
    }
  
    .logo {
      margin-bottom: 0.5rem;
      font-size: 1.2rem;
    }
  
    .nav-links {
      width: 100%;
      flex-wrap: wrap;
      justify-content: center;
    }
  
    .nav-item {
      padding: 0.3rem 0.8rem;
      font-size: 0.9rem;
    }
  
    /* 検索フォーム */
    .search-section {
      padding: 1rem;
    }
  
    .search-form {
      flex-direction: column;
      gap: 0.5rem;
      padding: 0 1rem;
    }
  
    .search-form input,
    .search-form select,
    .search-form button {
      width: 100%;
    }
  
    /* 商品カード */
    .product-card {
      width: calc(50% - 10px);  /* 2列表示に変更 */
      margin-bottom: 15px;
    }
  
    .book-grid {
      gap: 10px;
      padding: 0.5rem;
    }
  
    .product-card h3 {
      font-size: 0.9rem;
      margin: 5px 0;
    }
  
    .product-card .author {
      font-size: 0.8em;
    }
  
    .product-card .price {
      font-size: 1em;
    }
  
    .btn {
      padding: 6px 12px;
      font-size: 0.9em;
    }
  }
  
  /* さらに小さい画面向け（iPhone SE等） */
  @media screen and (max-width: 375px) {
    .product-card {
      width: 100%;  /* 1列表示に変更 */
    }
  
    .nav-item {
      font-size: 0.8rem;
      padding: 0.2rem 0.5rem;
    }
  
    .featured-books {
      padding: 1rem;
    }
  }
  
  /* タッチデバイス向けの最適化 */
  @media (hover: none) {
    .nav-item:active,
    .btn:active {
      opacity: 0.7;
    }
  
    /* タップ領域の拡大 */
    .nav-item,
    .btn {
      min-height: 44px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
  }