/* カテゴリ一覧（品目の目次） */

.category-index {
    padding-bottom: 40px;
}

.category-index__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

@media (min-width: 768px) {
    .category-index__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 992px) {
    .category-index__grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 20px;
    }
}

.category-index__card {
    margin: 0;
    border-radius: 6px;
    overflow: hidden;
    background: #fff;
}

.category-index__summary {
    display: block;
    cursor: pointer;
    list-style: none;
}

.category-index__summary::-webkit-details-marker {
    display: none;
}

.category-index__hero {
    position: relative;
    display: block;
    border-radius: 6px;
    overflow: hidden;
}

.category-index__image {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    display: block;
}

.category-index__overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 8px;
    padding: 36px 14px 12px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
    color: #fff;
}

.category-index__title {
    font-size: 1.1rem;
    font-weight: bold;
    line-height: 1.3;
    color: #fff;
}

.category-index__overlay::after {
    content: "＋";
    flex-shrink: 0;
    font-size: 1.1rem;
    font-weight: bold;
    line-height: 1;
    transition: transform 0.2s ease;
}

.category-index__card[open] .category-index__overlay::after {
    transform: rotate(45deg);
}

.category-index__panel {
    padding: 12px 4px 4px;
}

.category-index__parent-link {
    display: block;
    margin-bottom: 10px;
    padding: 10px 14px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background: #f5f5f5;
    color: #333;
    font-size: 14px;
    font-weight: bold;
    text-decoration: none;
}

.category-index__parent-link:hover {
    background: #eee;
    text-decoration: underline;
}

.category-index__children {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 10px 12px;
}

.category-index__children a {
    display: inline-block;
    padding: 8px 14px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
    color: #337ab7;
    text-decoration: none;
    background: #fafafa;
}

.category-index__children a:hover {
    background: #f0f7ff;
    border-color: #bcd;
    text-decoration: underline;
}

@media only screen and (max-width: 767px) {
    .category-index__overlay {
        padding: 28px 12px 10px;
    }

    .category-index__title {
        font-size: 1rem;
    }
}