/* ========================================
   書籍ページ専用スタイル
   ======================================== */

/* ヒーロー風ページヘッダー */
.books-hero {
    background: linear-gradient(135deg, #1e5ba8 0%, #2c7be5 100%);
    padding: 120px 0 80px;
    margin-top: 70px;
    position: relative;
    overflow: hidden;
}

.books-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><rect fill="rgba(255,255,255,0.03)" width="50" height="50"/></svg>');
    opacity: 0.5;
}

.books-hero .container {
    position: relative;
    z-index: 1;
}

.books-hero-content {
    text-align: center;
    color: white;
}

.books-hero-title {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.books-hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.books-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 3rem;
}

.books-stat-item {
    text-align: center;
}

.books-stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.books-stat-label {
    font-size: 1rem;
    opacity: 0.9;
}

/* フィルターセクション */
.books-filter {
    background: white;
    padding: 2rem 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    position: sticky;
    top: 70px;
    z-index: 100;
}

.filter-tabs {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dark);
    cursor: pointer;
    transition: var(--transition);
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
}

.filter-btn.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 12px rgba(30, 91, 168, 0.3);
}

/* 書籍一覧 */
.books-list {
    padding: 4rem 0;
    background: var(--bg-light);
}

.books-category {
    margin-bottom: 4rem;
}

.category-title {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.category-title i {
    font-size: 1.5rem;
}

.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.book-item {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.book-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.book-cover {
    position: relative;
    width: 100%;
    height: 400px;
    overflow: hidden;
}

.book-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.book-item:hover .book-cover img {
    transform: scale(1.05);
}

.book-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.7), transparent);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 1.5rem;
    opacity: 0;
    transition: var(--transition);
}

.book-item:hover .book-overlay {
    opacity: 1;
}

.btn-preview {
    background: white;
    color: var(--primary-color);
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.btn-preview:hover {
    background: var(--primary-color);
    color: white;
    transform: scale(1.05);
}

.book-details {
    padding: 1.5rem;
}

.book-tag {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 0.35rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.book-details h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.book-excerpt {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.btn-amazon-small {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: #FF9900;
    color: white;
    padding: 0.6rem 1.2rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
}

.btn-amazon-small:hover {
    background: #e68900;
    transform: translateX(5px);
}

/* レスポンシブ */
@media (max-width: 768px) {
    .books-hero-title {
        font-size: 2rem;
    }
    
    .books-hero-subtitle {
        font-size: 1.1rem;
    }
    
    .books-stats {
        gap: 1.5rem;
    }
    
    .books-stat-number {
        font-size: 2rem;
    }
    
    .filter-tabs {
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 0.5rem;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
}